I had the PG BB stinker too. I found keeping it dry helped. I would even go as far as to blow dry it after my shower. That helped alot. My husband had a lot of stinky belly button jokes, the things women go through!
I get that stank button too homegirl LOL :o) Try Cornstarch? I haven't. I just make sure I dry it really well after I get out of the shower, and this usually eliminates the problem. If I forget then it smells pretty gross.