I’m not questioning you here, because you’re a mod, and I respect your superior body of knowledge….
You can question anytime, mods (or vets in general) are not supposed to have perfect knowledge of PE.
…..But how can I know, for my own future benefit, whether the CS or CC is retaining fluid?…
Eyes and feeling should be enough to notice where the pressure is going. Inflating CS serves to nothing but creating risks for the urethra.
Also, I notice in Mem’s Momentous Rapid Gain Mechanism he utilizes Horse440s. I can only assume he experienced some significant growth from his own program. Do you think the growth he experienced just came from the dry jelqs and modified sadsaks?
There are several exercises in that routine, so hard to say what worked and what not. Beside that, one single case will never say anything significative.