Ahhhh... That is actually i wanted to listen.

Here are my 2 cents .

Yes in my last company , we also had same kind of requirement. so what we did , we created another database to store these temp tables (actual physical tables) and then used them. and we also kept them on separate disk. in this way you dont put extra overhead on your sql server (on user db or tempdb) put cleaning/droppping tables will also not impact the peorformance.

So you need separate database.