I use hydrogen peroxide on a cotton ball.

You can use the stridex medicated pads too, but I try to stay away from medicated things, in case they have a reaction to it.

I have a foster right now that has a big black spot on her chin, and she won't even let me get near her to put the cotton ball on it.

Snowy loved when I rubbed his chin with the ball, the smell of the peroxide didn't bother him either. His is all cleared up.