I am not sure if Ivory soap still is made with lye.
One place list the ingredients for Ivory soap as:
Ingredients
Sodium tallowate, sodium cocoate or sodium palm kernelate, water, sodium chloride, sodium silicate, magnesium sulfate, and fragrance.
(It is interesting that magnesium sulfate (Epsom salts) is one of the ingredients.)
Somebody else list the ingredients as:
Ingredients:
Sodium Tallowate and/or Sodium Palmate, Water, Sodium Cocoate and/or Sodium Palm Kernelate, Glycerin, Sodium Chloride, Fragrance (Parfum), Coconut Acid (Contains One of More of These Ingredients), Palm Kernel Acid (Contains One of More of These Ingredients), Tallow Acid (Contains One of More of These Ingredients), Palm Acid (Contains One of More of These Ingredients), Tetrasodium EDTA.
Product Description: Ivory Bar Soap, Simply Ivory 9.5 oz.
https://www.wegmans.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10052&productId=360775&catalogId=10002&krypto=QJrbAudPd0vzXUGByeatog%3D%3D&ddkey=http😜roductDisplay
This is the Wiki page for sodium tallowate. I am not quite sure if this goes on in all soap making or this is a process if modern chemistry?
http://en.wikipedia.org/wiki/Sodium_tallowate
That Wiki page talks about Saponification but it is probable not worth going to look that Wiki page at but there is a link to a "Simplified diagram of the saponification process" which is kind of interesting. You end up with a molecule with one end having an infinity for water and the other end having an infinity for oil. (getting oil and water to mix)
http://en.wikipedia.org/wiki/File:Soapsap1.gif
After reading the Wiki on soap I am still not sure it sodium tallowate is the same process as lye and animal fat? Here is the wiki on soap:
http://en.wikipedia.org/wiki/Soap
I was hoping to know it all by now --- Fred
P.S. Have you ever thought about putting an anionic surfactant in your butt?