As with Rick I would use a heartbar and have owner keep clean and dry. You can use thrush buster, merthiolate, or fungidye. At each reset you need to keep a good watch to see if you need to debride any more infected area out. Clean, dry, open to air and light. Heartbar and makesure you get all the infected area removed.
Horses are extremely susuptible to tetnus.
As for epsom salts and WLD, It should help pull any microscopic fungal particles and the same with the sugardine. It would be for a week to be sure it was healing well. Especially if the hole was to be allowed to pack with dirt, mud and manure. Epsom salts help and prevent scar tissue and would help in healing a more normal hoof wall. I would clean the effected area and keep it clean.