*Brakteaten as in people not hoarding money that will eventually lose value, so wanting it to work for them, thus driving the economy.
At first I thought this was an interesting idea to discourage hoarding. But then I realized that the hoarders would just use brains to figure out how to launder money back to themselves to avoid expiration. Or even worse simply find alternatives stores of wealth as is described here http://p2pfoundation.net/Brakteaten_Money:
“Between the 12th and the 15th century in Europe a money system was used called "Brakteaten." Issued by the respective towns, bishops and sovereigns, it not only helped the exchange of goods and services but also provided the means of collecting taxes. Every year the thin coins made from gold and silver were "recalled," one to three times re-minted and devalued on an average about 25 % in the process. Since nobody wanted to keep this money, people instead invested in furniture, solidly built houses, artwork and anything else that promised to keep or increase its value. During that time, some of the most beautiful sacred and profane works of art and architecture came into existence. "For while monied wealth could not accumulate, real wealth was created." We still think of this time as one of the cultural culmination points in European history. Craftsmen worked a five-day week, the "blue" Monday was introduced and the standard of living was high. In addition, there were hardly any feuds and wars between the various realms of power. However, people obviously disliked the money which lost so much at regular intervals. Finally, towards the end of the 15th century, the "eternal" penny was introduced and with it came interest and accumulation of wealth..." (www.margritkennedy.de)
See also information on the above author at http://userpage.fu-berlin.de/~roehrigw/kennedy/english/
So you would probably see people dump a brakteaten-bitcoin currency. Or you could enforce mandatory use of such a brakteaten-bitcoin currency with a violent monopoly.