One important lesson  I learned from my son  Izhak [aka Nahman] is specifically not to add nor subtract from the commandment of the Torah. \This in particular is relevant to sexual sin where it is common for people to add restrictions which then leads them to transgress real ones.  The secular world demises all the prohibition of the Torah, and so in place of them, they make up new ones. On the other hand, the religious world makes up new restrictions, and by that transgress actual prohibitions.

Examples are fairly well known, concubines [or mistress] [''girl friend''] is permitted to most rishonim [mediaeval authorities.] But the Rosh bring the problem that she might be embarrassed to go to the mikve. But I do not think  mikves are okay anyway since they are made from concrete which can be lifted out of the ground in one piece--so they are vessels. And one who dips in a vessel is not made clean. הטובל בכלים לא עולה לו טבילה Instead one might go to the sea, or river, or have the concrete thin enough that it would nor be a vessel. But nowadays, often when making a pool or mikve, there is put some layer of plastic under the concrete. That, in any case, makes the mikve invalid.   

[I might add that clothing is not a separation חציצה from water since the water can and doe get through the clothing.]