||Dear Rabbi CYA,
Someone I know is not yet ready to go the mikvah. I have recommended that she start going to the local pool, figuring that at least min ha-Torah she will be tahor, and that is better than nothing (and gets rid of the karet issue). I know that we cannot assume that all pools are OK as kosher mikvaot, since it is possible that before the pool was filled, mayim sheuvim were used to clean it, and they remained in the drains. But mi-de-Oraita certainly such a pool would be kosher.
So my question to you, and please confirm with your father, is am I permitted to at least encourage a woman to go to the pool every month, as in this way she will lessen the de-Oraita violation? It's not a question of pool vs. mikvah but of pool vs. nothing.