FWIW I've never had an issue with scratching from those brushes. You just have to thoroughly blast it with the high pressure soap before using it.
If they are light, you can probably get them out with some Dual Action Cleaner Polish from Meguirs and a Dual Action polisher. Follow up with a coat of your favorite wax. If that doesn't work, you can step up to a Rotary Buffer with the same compound. If you haven't used one before, I recommend taking it to a body shop, because you can easily burn your paint with a Rotary Buffer.