I really don't see how more currencies or parallel currencies can solve the problem. At best, it can delay things. Frequent flyer miles, fast food discount tickets etc are all well and good; but they have very limited use/acceptance. In every society there's a hierarchy of money, and that which Gov defines as legal tender sits atop that hierarchy. The root demand for Gov money stems from Gov money taxation. All other demand for it stems from that. When you have private and public debts denominated in the Gov's currency, the solution is for the currency monopolist to satisfy the private sector's tax bill and its desire to net save or to simply declare a debt jubilee.
The former is certainly not an alien policy. It's been applied throughout history to one degree or another. It's even encouraged in the bible.
Having government give the status of legal tender to private IOUs might increase the monetary system's resilience to negative shocks - but it's certainly not a cure, and it's certainly inefficient. All monetary systems rely on the expansion of debt in order to produce growth, rather than social hardships. The problem is when the debt shrinks. And in our times, the problem is private debt, bank debt (aka inter-temporal arbitrage). When those private debts come due, people need to pay with HPM (high powered money, aka government debt), otherwise the banks take their things. And it's certainly a problem for the banks as well. When their assets (the loans they make) start shrinking in value relative to the deposits (the liabilities) they have, which stay the same. The country I live in, Romania, doesn't have a bankruptcy law for individuals. I envy those countries who do, and the US is one of them.

When Lietaer says that Government should issue the money, rather than the banks, I presume he's referring to the Eurozone. Well, yes. That's the piece of the puzzle. The Eurozone has a CB, but it needs a Treasury type of institution. Either that, or endow the CB with those prerogatives. The ECB can already function with negative equity - all that's lacking is the EC's political will to pursue the general welfare of the Union, rather than the petty interests of the oligarchy. Of course, I agree with Lietaer about the politics of the Nobel prize system, and the role of mainstream economics to serve the establishment et all.

In my opinion the solution is two-fold.
Getting rid of private ownership over natural monopolies (private ownership over non-man-made things, such as land, rivers, minerals, forests, and mountains). And getting rid of the FIRE sector, a sector which has nothing to do with the real/productive economy, and which is responsible for the highly inequitable flow of funds from high MPC households to low MPC households, which in turn cripples the real economy (non-financial firms and labor).
By having asset side discipline for the banks and providing a public banking option ONLY, which would issue loans to consumers and business without interest. We'd eliminate the drag and inequality in the economy, produced by compound interest and mortgage debt.

Here are the asset side rules for the EZ banking system (which can be applied to any country, really), which would serve and not sabotage public purpose, and would not require de jure federalization. Note: I prefer a public banking option only, but you can easily have it private if that fits your political persuasion.

1. The ECB to provide unlimited guarantee for euro deposits.

2. The ECB to lend unsecured to member banks, and in unlimited quantities at its target funds rate, by simply trading in the funds market.

3. Make a zero interest rate policy permanent. This minimizes cost pressures on output, including investment, and thereby helps to stabilize prices. It also minimizes rentier incomes, thereby encouraging higher labor force participation and increased real output. Additionally, because the non government sectors are net savers of financial assets, this policy hurts savers more than it aids borrowers, so a fiscal adjustment such as a tax cut or spending increase would be appropriate to sustain output and employment.

4. Banks should not be allowed to have subsidiaries of any kind. No public purpose is served by allowing banks to hold any assets ‘off balance sheet.’

5. Banks should not be allowed to accept financial assets as collateral for loans. No public purpose is served by financial leverage.

6. EZ banks should not be allowed to lend off shore. No public purpose is served by allowing EZ banks to lend for foreign purposes.

7. Banks should not be allowed to engage in proprietary trading or any profit making ventures beyond basic lending. If the public sector wants to venture out of banking for some presumed public purpose it can be done through other outlets.

8. Use ECB approved credit models for evaluation of bank assets. I would not allow mark to market of bank assets. In fact, if there is a valid argument to marking a particular bank asset to market prices, that likely means that asset should not be a permissible bank asset in the first place. The public purpose of banking is to facilitate loans based on credit analysis, rather than market valuation.

9. Banks should not be allowed to buy (or sell) credit default insurance. The public purpose of banking as a public/private partnership is to allow the private sector to price risk, rather than have the public sector pricing risk through publicly owned banks. If a bank instead relies on credit default insurance it is transferring that pricing of risk to a third party, which is counter to the public purpose of the current public/private banking system.

10. EZ banks should not be allowed to contract in an interest rate set in a foreign country, with a large, subjective component that is out of the hands of the EZ member state governments.

11. Banks should only be allowed to lend directly to borrowers, and then service and keep those loans on their own balance sheets. There is no further public purpose served by selling loans or other financial assets to third parties, but there are substantial real costs to governments regarding the regulation and supervision of those activities.

12. The ECB should buy EIB (European Investment Bank) bonds, financing thus projects of public interest in and among member states - without there being a need for further deficit spending for member state governments. The later have the liberty to focus on fiscal policy (deficit spending included) for their own domestic purposes.

PS: The bulk of the proposals belongs to Warren Mosler. Number 12 belongs to Yanis Varoufakis, and not just to him but to S. Holland and J.K. Galbraith.

PPS: In conclusion, I want to say this. Regardless of what you implement, regardless of how good it may be - at the end of the day, people are fucking stupid. And they're everywhere in every strata. Stupid rich people. Stupid middle class people. Stupid poor people. Stupid working people. Stupid unemployed people. Stupid men. Stupid women. Stupid trans people. Stupid heterosexuals. Stupid homosexuals. Stupid theists. Stupid atheists. Etc. At the end of the day, that good system which was in place will erode, and people will allow it to fall because they're fucking stupid and greedy.
I'm not being a fatalist here. I'm simply using Ibn Khaldun's theory on society.