>>>Nope - in this case you would have other applications data there too.
>>
>>Then your application is badly planned. Every application should have some maintaince function, where you can reindex and clean up once in a while.
>
>How would you clean after yourself if you're sharing the temp folder with other applications?

By NEVER sharing a temp folder. I have one separate temp per application I create.

>Also, I don't see why re-index and maintenance comes into this topic at all.

You mentioned deleting "dead" temp files, which I think should be taken care of by a separate maintainance module. In my applications this maintainance module also has options for recreating indexes and similar stuff, which only should be done very rarely.