I have been sounding with various objects for as long as I can remember. The handle of a darning needle was my first tool. The handle worked ok, but I wanted more. I've gone from pens, to dowels, Q-tips, any thing I can find.
When sounding alone didn't give enough stimulation, I moved on to adding soap, and then powdered Comet. Now I have self made composite rods that go in dry with pee holes and see how long I can stand them.
I happened to have a bumper crop of really hot peppers in my garden this year. It occurred to me they would give a good burn. They might be just about the most perfect pain one can give themself. I started by rubbing one up against the head a little. When I stopped, I thought, that didn't do much. But then the burn started. After an hour I wasn't sure I'd be able to tough it out, but then it subsided.
Of course, my next thought was to rub the pepper on a Q-tip and sound. It starts slow, reaches a point that it's almost unbearable for a couple hours, then diminishes again.
I'm going to record it for here sometime.
Oh yes, apparently using hand soap or dish soap afterwards will take the burn away, if anyone tries it but then wants to reduce the pain.