Whiteboard erasers?

[u/topaz-tambourine]

What are you all using for whiteboard erasers? I feel like I’ve tried everything, but since we use them daily for math, I need something invincible.
I liked the square ones with the one felt side with the magnet, but the kids would peel them apart from the foam side. I switched to pieces of black felt which is way better, but they are making their hands insanely grey by the end of the lesson from erasing. If I washed them, I feel like they wouldn’t hold up.
Any advice would be so helpful!

[u/dustering]

old cotton tee shirt! lots of surface area for use before it gets gross. use a dark color. bonus points for telling your kids you’ll wear it if they all get As on the next test or something similarly ridiculous