Those might be great tips if you prepare your rabbit for a show, but for just cleaning mud off feet a shallow (1/2") pan with lukewarm water without any chemicals, detergents, acids or whatever will do perfectly.
Or just wiping the feet with water. Don't bath the whole bunny, and rub the places you needed to wash dry with a towel afterwards.
I wouldn't use anything else for just mud since somewhat discoloured feet really don't matter, at least I don't put stuff on my rabits for cosmetic reasons.
If it's (too much) pee or poop the stuff mentioned above may be ok, but I would rinse thoroughly, and not use it on a daily basis.
Water is not a no, far from it, just don't dunk the whole bunny in it, bathing rabbits is a no.
My rabbits look quite grumpy when out in the rain, but it doesn't hurt them in any way (they come in before their body is soaked completly, but their feet definitly are).