Mel, you could try a product called DuoDerm or Replicare. Something similar I have been able to find at Wal-Mart is a band aide product used to cover blisters. They are a "hydrcolliod" dressing that is made to stay on for a minimum of three days. When I was working HomeCare I would clean the wound GENTLY with soap and water, rinse well with normal saline (to make your own boil water and add 1 tsp salt to 1 quart boiled water, can seal in Mason jar or keep in ref for 1 week no longer) then if you wanted to apply a drop of the silver let air dry and apply the dressing. I would use a Metaplex tape ONLY if needed to keep in place for three days. Another product is Spenco "Second Skin" it is a saline based gel that is changed daily, more of a cushion. Like Mrs D said, I would not leave it openwhen he is up on it, too much risk for infection. Along withe the zinc and C I would increase his protien intake (unless he is experiancing renal failure). A wound consult would help with insurance.
Good Luck!
pooh