Take a stain stick (or spray) and spray the marks thoroughly. Then take a soft toothbrush and gently brush the marks in all directions. Let that sit for at least 30 minutes (the longer the better), then wash with a GOOD liquid detergent. I personally like the old Wisk. It's gotten out dried shellac, dried blood and all sorts of stuff for me in the past. Good luck, and let us know how it turns out.