I can't believe these words are coming out of my word processor!
For the moment, let's just say that I'm at the "certain age" that came a generation or so after all the hoopla about laundry detergents, hand soaps, shampoos, and other cleaning products and lather. Personally, I bought into it; completely. Now, it just doesn't want to leave my brain! It's that ingrained. It was pounded into me as a youngster.
Somewhere around the turn of the 20th Century, some marketing genius came up with the idea that their company could "outsell" the competitors by using the amount of lather as proof of cleaning ability. I'm saying this was the brainchild of a marketing person because the "chemists", the people formulating the product, knew full well that lather had little if any affect on cleaning ability.
The point is, great grandma, maybe even great-great grandma bought off on this proposition and passed it down as "fact" to the rest of us. A given.
You can see it all around you in various advertising campaigns. I guess it isn't going to go away. It's too hard to replace 100+ years of indoctrination. So, what to do? Well, tell the chemist to add a foaming agent to products where they are demanded.
A little background. Prior to the 1970's, manufacturers added specifically formulated phosphates to laundry detergents to make the detergent lather more. In my opinion, it was done mostly to create more sales. (I was unable to find any definitive evidence to prove or disprove my opinion, but found many people holding such opinions.) At any rate, many of our streams, rivers, and lakes where effluent (wastewater, either treated or untreated) dumps, began to get covered with a green slimy film. To put 20 years of history in one sentence, by the end of the 1980's Federal and State Governments severely curtailed the use of phosphates in laundry detergent to solve the problem. The fact remained, that most of the cleaning products worked just fine with much less lather.
To add lather and foam to modern products, manufacturers turned to synthetics such as MEA, TEA, and DEA. As best I can determine, their only purpose is to is to make shampoo lather-up to peoples' expectation. There may not be much of a downside to these synthetics, but do you really want them on your dog's skin where they can be absorbed into their body?
Coconut oil (also called the fruit of life) has naturally occurring surfactants and foaming properties. Friction, such as rubbing your dog will also increase the lather. It works best when the dog is very wet from water. The temperature of the water is not a factor. Water temperature is a factor of the dog's comfort.
So, how does this work?
The surfactant allows the water and oil to combine. This is through positive and negative polls on the resulting molecules. The oil and dirt on the fur and skin is attracted to the negative polls and unattaches from its surface and forms small spheres (called micelles) that becomes trapped or suspended in the water. The oil and dirt go down the drain with rinsing.
Lather is the result of making water wetter. The surface tension of the water is increased which allows water to cover the oxygen, thus forming a bubble. There can be some benefit to having the bubbles, but apparently it is only significant to the observer (us). What really matters is that the micelles form and are rinsed away.