There are all kinds of products out there to use from commercial to homemade. I keep the area around my water tank moist, not soupy wet but keep the ground soft. Then The day prior to the farrier coming out I will soak their feet in water for 20-30 minutes am and pm. and then hopefully before he gets there. But some horse will just have harder feet than others. I have one that no matter how much soaking or topical rubs nothing works she just has hard feet.

Good Luck