ester
Not slacking multitasking
Your horse has some infection in the hoof wall that looks to me to be pretty severe. If your farrier cannot suggest how to put it right I think that you need to look at two things:
1. disinfection. there are several products which will do this, I use hydrogen peroxide at 3% and I would be using it daily on those feet.
2. nutrition. Crumbling hoof wall like that is often caused by dietary problems. The first guess is always too much sugar, but mineral imbalances can be an issue too. If you do a search on the forum you will find plenty of information about both.
Unless you know that yoru horse has a metabolic problem like Cushings and are already treating it, it looks to me like you could have some nasty trouble brewing there that needs to be got on top of.
CP I think they are motor's feet and iirc he does have cushings. I am sure eaglestone will correct me if wrong!