Taint will go away if Steele goes long enough without aquiring more taint - IIRC if you go a couple of days without getting more taint, then it will start to roll off at 1% per game day. So if your Steele is at 50%, then you need to go about 52 days without getting any more taint and you should be back to zero.
Taint reduction services, given what I recall of in game lore will probably require an untainted/pure genetic sample from before someone was tainted. The PC's nanites probably have a couple templates of their genetic code that allow that. One from birth for control, and another that updates with physiological changes, and etc. Even then there's probably crap that can't be cleared out entirely via nanites,or damage that can be entirely undone.
The Doc on uveto should be a to issue the treatments easily.
Also an easy way to say why Victor ended up so bad in the end.