Yeah, that's what I'm seeing too. The stuff that sucks my boots off and takes a screw driver to remove after it dries on their feet. No lie, I have had to take them to the wash rack 2 or 3 times to soften in up enough. I thought about soaking in buckets but that's one of those things I would run by my trainer first:')
Yes, it used to be like that at the military stables where I kept my horses before I moved here.
What I am saying is, a little hooflex or some kind of grease before they get into the mud, seals it, and the dried mud should be eaiser to remove.
I used to have to chip it out with a screwdriver!