im just not an advocate of topical mms . I think its not reaching deep enough and irritates the skin more, temporarily you might see a change and it will get worse coz mms isn't going deep enough .
and you cannot keep applying it on your dogs sores. mms burns tissues if you don't dilute it properly as well. have used it on my face and burnt it when I used it first time 10 years ago, used it on my gums, burnt them, and got ulcers before they healed in a few days etc.
so putting it on your dog, if you don't dilute it enough your putting your dog through hell. if you are going to do it anyway , first try it on the body for a few days to see how the dog reacts and yelps etc. because you are in no position to put a mute dog through hell, just because you feel you are doing a good thing.