I got involved with trying to help "frigid" woman back in the 50s when Masters & Johnson developed a sort of "treatment plan". I didn't use their plan, but I did use what they had learned about married women who were "frigid": they were not frigid. 99% of them were totally normal and most of those could be multi-orgasmic. A few were clinically psychotic- usually schizophrenic and pretty so nobody cared they were crazy. And a few had been parented by people who ruined sex for the woman.
So I simply screened out the few women who were crazy or parent-ruined and focused on the huge number of beautiful loving wives who simply had terrible lovers as husbands. They DID love the husband or they would have found sexual pleasure elsewhere (some actually had done that but were not about to admit it to her husband).
I explained to the husbands that if he would record a series of statements, his wife could use them and a machine we had developed to become orgasmic with marital sex. All of them were already orgasmic with masturbation, and some had found decent lovers and were orgasmic with THEM, so I could almost guarantee success.
I explained that the first few lessons would be WITHOUT his interruption, and then the next few would involve him. Most of these men were mostly interested in getting their cock in and shooting off-- NOT how much the wife did or did not enjoy it. I guess they assumed there was something wrong with a woman who didn't get excited and "come" from just being near his beautiful cock.