mms is acidic . it will make you lose your tooth enamel . so not a good idea.
but some of the experts on here, have suggested mixing a bit of baking soda to reduce the acidity so this doesn't happen.
you can ask some more of the guys on here.
I personally will never recommend swishing with something like mms which is acidic in the mouth . I have mms everyday , and it helps with my breath and body odour anyway.
I personally think hydrogen peroxide swishing is best for the oral hygiene. but note that its not a good idea to swish with hydrogen peroxide if you are a smoker. there is a link to oral cancer when it mixes with the nicotine in the. mouth.
I suggest using mms internally, but there are lots of guys here way way way more experienced than I am and have had success with swishing mms.
I just wont risk my enamel lost, non shiny teeth with discolouration is simply unacceptable to me.