But who will want worthless currencies?
Actually nobody!
Thinking about it, this is the fault of your goverent...
UK banks offer to exchange anything the central bank will accept and return sterling for (fiat wise -excluding gold and silver as you'd have to go direct to the cb). Why don't you have something like that there? And if you don't, why don't you get people to petition the government for it (even companies would probably go for that).