Using anything to clean a wound before granulation tissue forms and the new epithelial cells haven’t formed is OK with me. Personally I like a soap such as an iodine / povodine scrub plus physical abrasion as long as the horse will stand for it. However, after this 1st cleaning it is really important to not use anything that will destroy the delicate epithelial cells. This includes and hydrogen peroxide to antiseptic solutions or soaps. The only thing I recommend is either 1) 0.9% saline or 2) low pressure water from a hose gently flowing over the wound followed by a topical antibiotic powder (not an ointment). That is it.
When the epithelial cells are damaged the underlying granulation tissue can over produce causing proud flesh (exuberant granulation tissue). There are 2 reasons for proud flesh. The first is that the wound has not been seen for a while and care has not been applied. The second is because the attending human has destroyed the epithelial cells with solutions, ointments, gauze and / or physical scrubbing.
Review – Clean it like crazy. After this only a gentle flow of water to remove exudate. Apply an antibiotic powder onto a non-stick pad (Telfa, etc) and place that on the wound. Add a layer of gauze for padding. Apply a stretch wrap such as Vet Wrap with a small amount of pressure. Seal the top and bottom of this with an elastic bandage with glue (Elastikon) to keep the dirt out. Replace this bandage about every 3 days (not every day).