Baby wipes do wonders when you are in a hurry! Also baby powder is good if their legs are on the white side or you could even use it on the horses body. You just simply rub in into the spot with the stain. Also keeping your horse clipped can help keep the stains from soaking in. And of course a regular bathing schedule and keeping theor stall clean (if they are out side that can be difficult) green spot remover can always help aswell. And a good brushing is always a good start
Purple shampoo works wonders!
There’s this thing called Moisture, it’s a horse cleaning spray and a life saver! 10/10 reccomend it.
Baby wipes, a really good brushing, and lots of purple shampoo. For some reason, baby wipes are good at getting out stains. If you're near the beach, tide water is great at getting out yellow marks too so we often ride the horses in to their hocks/knees and hose them off when they get back. Chalk can cover any stubborn patches for shows.
Other than that, just keeping the horse clipped, keeping the stable clean, using rugs etc to stop stains. It's not easy though, especially if your horse is determined to be dirty!