I know that, I need to get clean coins for my eth from tornado cash that is now marked as mixer by aml checkers. What service can I use to get clean usdt?
I think you should do some p2p swaps including through private coins like monero and use a new address as USDT receiver. Think about the time lag and gradual exchanges.
I can't recommend any p2p exchange for this particular situation, but a popular one on this forum is exch.net. If it is possible to contact support at each exchange you're gonna deal with, you should consult with them first.