only way of loosing taint is going 3 days without gaining taint, so... just waiting... yeah... at least you can play the game "normally" and still lower taint
as for the consequences in the story maxing out means you reached a "bad ending" for when the game finally finishes
in gameplay the consequences you get the "Corrupted" perk which increases your maximum libido to at least 200 and prevents taint losses
and the "taint" stat determs your minimum-libido amount and in general having a high libido amount isnt great, for example a lot of Willpower checks use your libido against you and personally it gets annoying really fast
