Ross wants to know:
I dye my hair black on a regular basis, and I'm also a clumsy oaf. My bathroom wall has many spots of blueish-black. Some I've managed to get off with a toothbrush and paste made of water and Barkeeper's Friend, and a Magic Eraser made a little dent in some of them, but some seem to be determined to survive the next apocalpyse.
The walls are flat off-white over plaster, and some of the spots are a little old and set — before I discovered Barkeeper's Friend, I didn't think anything could get them off.
So what should I use on those stubborn spots? Would a bleach pen work, or just make a big white blob in the off-white? Anyone have a successful formula to get hair dye OUT, or are we doomed to paint?