I have tried doing this, and it 'seems' to have worked.  What temp should I be setting my oven to, and how long should I keep the parts in there.  

I usually take the bbls out of my pistols, and put them straight on the oven rack.  I then turn on the oven @ 350 for about 15 minutes.  

I've done this twice in the past year, which is about how often I have needed copper/powder solvent to clean them.  

Just found out that 350 is too hot- apparently 150 is about right.  Oh well...

Use a hair dryer or a heat gun. thats all it needs.