Heck guys, everyone knows it is a "heat gun"! ;)

Don't confuse the two. Especially if you're using it to take care of a jock itch.

Soak the part with Ballistol for at least a night, then rub it gently with an old toothbrush and Ballistol.
It will take some patience but I'm almost sure that you'll solve the problem without any damage to your pistol finish.
Good luck.