Also keep his weight DOWN! More weight puts more stress on his hocks. Sore hocks are, essentially, pressure sores. The less weight, the less pressure.
Keep his nails clipped, too. Long nails makes him lean back on his hocks adding more pressure to them.
Exercise! It will help to keep his weight down and it will infuse the area with blood helping them to heal.
Fake sheepskin may also help in the areas where he lounges. The thickness and "fluff" helps to equalize the weight distribution and takes some of the pressure off the hocks.
If he bleeds, VET VISIT! Sore hocks can go all the way to the bone, damaging the bone and tendons! In severe cases, amputation is necessary.
Pain management, too, if he "pops a hock". You'll know if this happens by the scary amount of blood coming from the hocks. That's a definite VET VISIT! No waiting, no fooling. Now is not soon enough.
Watch for infection, too. Nolvasan is a good cleanser. Don't use HYDROGEN PYROXIDE!! EVER! Not on anything other than the carpet (it's a GREAT carpet cleaner) Hydrogen Peroxide can actually push the bacteria into the wound worsening the infection.
As stated previously Neosporin (NOT Neosporin PLUS) and Preperation H are also good to use.
Good luck. I've been dealing with chronic sore hocks for a couple of years. The best we can get is pink naked hocks with no abrasions and/or open sores.
