Hi , I'm James DVM MRCVS and would like to help you with your question
there have several studies into the dermal disease and it was found that a once a week used of antiseptic solution would be even better the the use of antibiotic as well as would not have the same effect when regarding withdrawal periods
There are several antiseptic you can use , though you must as well consider environment effect such as earth and water contamination
copper sulfate is one of the agents but again contamination should be considered if used on a large group of cows. another product which has been used on horses as well is called Kevin bacon hoof solution - http://www.kevinbacons.com/en/solution.html
You can get it in the uk .
Usually used once a week at first for at least a month and then reduced to once every other week for another month .
is important to provide a dry grounds well , otherwise you might be contaminating other members of the herd as well as causing a relapse in patient zero .
I hope this helps . let me know if you need my help further.
All the best.