So, not being not really caring which shampoo is "best" but which is cheap, I decided to try the cheap brand of Trader Joe's Shampoo. I've been Googling/Wikipeding the more complicated sounding ingredients. Most of them seem natural.
Just for fun, I'm looking at the 27-letter ingredients on Pert Plus. A lot of them are coming up on a website called, "" And I just found one called Methylisothiazolinone which seems to cause neurodamage in rats.