This could be a very good discussion. I am no chemist, so is there really no direct correlation between a product’s pH level and its cleaning power?
I wouldn't go so far as to say there is
no correlation, but I would say that focusing solely on pH and ignoring everything else isn't the best way to go about it.
If you consider water is a pH of 7 (it can vary, but for this purpose we'll say 7.) Dawn dish soap has a pH of 7.4, and it's notorious for breaking down grease and grime. I don't think anyone here would agree that Dawn is equal in effectiveness to just plain water when it comes to cleaning. If pH was really the only thing you had to focus on (Scott certainly is focused on it) then Dawn shouldn't be able to do anything more than water can do, which simply isn't the case. I'm no chemist, but if pH were the sole deciding factor, the above wouldn't be true.
Aside from pH, the different surfactants, and their varying strengths and purposes, play a huge role in determining cleaning ability. It's possible two soaps with the exact same pH level can have wildly different cleaning properties. In my experience over the years with varying car soaps from several manufacturers, I've never noticed a significant difference in cleaning ability between them.
This is also evident in this video:
https://www.youtube.com/watch?v=YWtUKIygT8U
If pH were the main concern, then blech-white, super clean, and super degreaser should have accomplished the same amount of cleaning (they're all the same pH) on that floor mat, but the surfactants in blech-white are different.
Whatever surfactants are present in the soap he is using are just different than other, pH neutral, car soaps. It would have to be, especially if this soap is marketed towards cleaning boats (which it is.)
Again, I'm not expert, and I'm always open to being taught something I don't know. I love Scott's videos, because like Garry Dean and Darren Priest, he honestly just keeps it real. Which I really appreciate. He speaks sensibly about a lot of things, but his focus on pH neutral soaps being useless just really bothers me in a big way, because he presents his subjective opinion as an objective fact.