They work on those "I've got to mark my territory" dark places on door facings & wall corners where my black cat rubs himself. This is a quick fix -- the paint may wear slightly but not seriously. Don't know if light-colored cats leave the same marks.
__________________ No matter how simple it seems, it's complicated.
Why? I have used commercial dips on silver jewellery and it works best on stuff that isn't too badly tarnished, and of course, stuff that doesn't have a pattern that needs patina.
I only offer a word of caution so no one dips Great Aunt Minnie's lovely heirloom brooch into it and ends up disappointed with the decision. I have not had consistent results, some items end up looking sort of raw and lifeless, others are sparkling and fresh.
I love magic erasers! I have 7 boxes of them in the cleaning supplies cabinet. They were on a good sale a while back. As mentioned though, I'm very careful about using them on painted or finished surfaces.
Grandchildren fill the space in your heart you never knew was empty.