If you really are concerned about tainted bitcoin just open a lightning channel and spend away.

Or buy a channel from an LSP with inbound 'space'... spend to it with the 'tainted' utxo then close the channel now that the lightning channel is full. You now have a utxo you own that has at least no on-chain link to the other one. The 2 never 'touched'.

One day in the future when bitcoin is mass adopted most transactions will be via lightning... so you won't send or receive UTXOs at all. Your lightning channel increases or decreases in size but the underlying utxo never moves.