Rubber mats are going to be your savior. At shows with concrete flooring I like to bed in straw, and usually bed up to the knees of the horse, and bank the walls. With rubber mats, I will bed with shavings or straw and usually only have to put enough so there is 1 inch around the entire back 3/4 of the stall (away from the feed and door).
As far as the hock sores, if they are "capping" (filling with fluid), you're going to need to cold hose or ice them for about 20 minutes every day to keep them from permanently capping, which looks ugly and can depreciate the value of the horse. As far as a topical, if there is no open skin and if it isn't oozing I would use a lanolin based product (or just plain lanolin) to keep the skin soft and pliable. If there is fluid coming out, you need to be careful it's not joint fluid, which is going to be very thick and very sticky, in this case you will need to get a vet out (it is very unlikely). If it is just normal clear fluid, that is just the wound flushing itself with white blood cells, don't worry about it. If the fluid gets yellowy then there is an issue. If it is open, I would keep if clean and allow it to heal before applying the lanolin.