I was on YouTube and saw someone cleaning coins with a product called MS70 cleaner for gold silver ect. Has anyone used this and if so what do you make of it? And do coin shops use this?
Yes. Depending upon the contaminents on the coin (i,e, grease, finger grease, etc.) copper coins can turn anywhere from blue to violet.
If I recall correctly, they changed the formula within the past two years; the older formula worked better from what I've read, but the newer in is less harmful to your health and/or environment. How old was the video you watched?
I use it sometimes to clean dirty silver coins. It works great on them and I really love the product. The only problem I have is that it makes the coin feel different, almost slimey. Self Slabbers typically can take a dirty, or blackened morgan and clean it up, put it in a slab, and give it a fake grade. I happen to love those dark morgans(with amazing details). If I was going to clean a silver coin, it would be with ms70 cleaner.
MS70 turning copper blue is well known and has been discussed on various message boards for several years.
I'm not sure how old the video was but it looked fairly current. Guy had like 50 videos posted and the one I saw was probably in the 10 most recent. So I would guess in like the last year