How safe and how is salabrasion done properly to achieve best results?

I prefer the right laser for tattoo removal.  It will usually take multiple treatments, especially when multiple colors are involved.

Salabrasion is not a reliable method for tattoo removal. It also carries a high risk of scarring that cannot be minimized. Spreading of ink within the body causing problems, other than allergy, (if you are allergic to the ink)  is purely speculative. There has never been a confirmed report of cancer in relation to tattooing or removal. I would suggest you seek out laser treatment, ideally with Picosure.