I would say you've done everything you can and the sheep should be fine, it might be worth bringing them in for a couple of days on a clean dry bed (I did this with mine) as it gives it chance to heal without getting mud, stones etc in it.
I did something similar yesterday, we only have 6 pet ewes who have just produced our first lovely bunch of lambs. one of them had a slight runny bum so I was bathing it, a couple of bit had dried so I very carefully trimmed the fleece of and accidentally cut the lamb. I felt terrible (the lamb didn't even notice) but I just bathed it with the disinfectant and applied antibiotic spray, seems to be healing and the lamb is running around none the wiser !