I swear, I cannot make this stuff up. The peppermint soap label used to say:
"11th: Essene & Chinese birth controls must reduce birth or Easter Isle type overpopulation destroys God's Spaceship Earth! God's law prevents all conception below pH3. Therefore, Essene contracepted for 400 years with rosehips, pH2! So, absolute clean, apply vaseline, oil, butter or cream, insert teaspoonful juicy lemon pulp, pH2. O.K.! Next day, douche with qt. soapy water, pH8, restoring pH5 balance God made! Eggwhite is pH9, Dr. Bronner's Soap, pH8, guaranteed the mildest made; below pH8 soaps biodegrade, synthetic-sulfides cannot. At conception, 10 grams contain 100 million humans! or... 10 humans in 1 invisible microgram - smaller than dust! Absolute cleanliness is Godliness! Then, who else but God gave man Love that can spark mere dust to life! The Moral ABC, uniting All One, brave, all life. Who else but God! Who else!"
I don't personally know anyone who has tried this, and certainly not successfully.
StraightDope.com had something about it too, I think.