I think throwing some shoes on would help, not only for future soundness in his work, but shoes would effectively raise the sole and the frog off the gound, taking the pressure off them and taking the brunt of the weight when the horse puts his foot down. It would also help to take the pressure off of a stone bruise that has already occured. Stone bruises can be a pain and sometimes are best dealt with by a farrier. With a bruise, there is a blood pocket maybe large or small sitting under the sole and you have to dig to find it, but if you are successful, the blood will drain out immediately, relieving the pressure and the pain right away. Otherwise, it will take time for the blood and the pressure/pain to dissapate. On an unshod hoof, the brunt of the footfall weight is not on the outside wall, but if you take two fingers and place them on each side of the tip of the frog, that where the weight falls, that, and the fatter heel part of the frog. I've had a good farrier that was very knowledgeable tell me that if you paint on iodine for three days in a row, it should toughen up the sole, but you've got to quit after three days, no longer. The iodine, in effect, burns the outer sole membrane, establishes a thick layer of dead cells that are toughened, thereby providing a protective barrier to the sensitive nerve endings. Shoes can be expensive and if your horse throws one, you are left with a really sensitive foot (like going barefoot for the first time yourself) and he's out of commission until the farrier shows up again. For some of us out in the boondocks, shoes are just not a convenient option. I've heard lots of good reports on those Old Mac Boots. They look hilarious when they are on, but they work and aren't as costly as shoes are.
This farrier I had retired his practise to go work full time in a zoo, and I'm not really sorry to lose him. Although he was very knowlegdeable and informative and knew his stuff, especially when it came to hoof trauma, he had a shoer's mentality and pared my horses hooves down to shoe applying level (I don't shoe) and pared down the frog with it. They couldn't move for two weeks after he left, so I complained, that's when he told me about the iodine, but I realized that it was only a cure from his visit, that he shouldn't be leaving my horses this way. His explanation was, well people generally don't take care of their horse's feet and I like to trim them right down so that dirt can't get a foothold in there and they don't have problems like thrush the next time I come. I continued to tell him that I DO take care of my horse's feet, so leave it, I'll clean it, but he wouldn't listen. Even the frog, naturally only sheds 2x a year and he was peeling it down to nothing every 6 weeks! No wonder they didn't want to move! So I found a new farrier that is "barefoot friendly" and haven't had to use the iodine since. But it will help you, but only 3 days, no more. And if your horse already has stone bruises, I'd find them and drain them before you apply the iodine, cause it will only make it harder to find them. Good luck!