Short or long? Either way, I think you will not see significant gains either way. In the short run, the currency is not seen as stable. In the long run, the currency, even if it seems stable will experience high amounts of inflation or stagflation for a quite a lengthy period. The lessons of Europe after WW2 demonstrate this quite well.
So you can not really call it a good investment whether you are going short or long, or using the strategy of buylow/sellhigh or buystrength /sellweakness.
For the record, I do not own either deutschmarks or dinars.
What remains the same is that the above is just an opinion.
Best of luck.