Comment 15 by Neodarwinian :

Misinformation about other STDs is also pervasive. Programs such as the Austin LifeGuard Character and Sexuality Education, used in ten school districts, teaches that there is “virtually no evidence” that condoms reduce the risk of the HPV (human papillomavirus) infection and alleges that “about a third” of all in vitro fertilizations can be linked to infertility caused by STD infections —in spite of evidence to the contrary from the American Society of Reproductive Medicine. At least one Texas curriculum, Wonderful Days, taught the dangerously false notion that “natural fertility regulation”— the rhythm method —has the “highest user effectiveness rate.” In an attempt to help students understand fertility, Wonderful Days offered an outlandish little rhyme: “If a woman is dry, the sperm will die. If a woman is wet, a baby she may get!”

What?!?!?

The sexist stereotyping does not concern me and that is Ms. magazine beating the ideological drum for all the wrong reasons. The above bold paragraph is so outre that if I had any hair left I would be pulling it out by the handfuls!

I think you will find that Wonderful Days is referring to cervical mucus. The rhythm method is not only about counting - undignified self examination is often also advised. There are more technical links out there, but I didn't want to freak you out with visual links.

Ridiculous rhyme of course, there needs to be an explanation of the difference between cervical mucus and vaginal lubrication for this to make any sense whatsoever, otherwise all that is being advocated for is painful intercourse.