Sorry to hear it was a big waste of time/money for you OP, I guess not everyone with ME/CFS has problems with lymph transit (assuming that's why you saw no real impact either way from the treatment)
I've been receiving PT on and off since April last year, and consistently since last summer/autumn. Along with adhering to my leaky gut protocol (not always terribly strictly) since around that time, the improvements seen over the period (impossible to say for sure whether they are coincidental or not of course), and arguably attributable (at least in part) to the PT specifically are:
Positive Observations:
• Improved congestion/inflammation of the cerebrospinal region (particularly upper back 'crankiness')
• Improved cognitive functioning (there's no way I would have been able to even begin to get my teeth into my research this time last year)
Drawbacks:
• Am pretty messed up by the impact of the body having to deal with processing the lymph for a good few days after each session with a practitioner (currently only monthly)
• Am a bit messed up for a couple of days if I do the full routine myself/with home help (usually just do everything except the back part, which I find to be the most exacerbatory)
• Precludes anything but very mild exercise * and I get the impression my POTS has worsened in this time. Can also interrupt sleep in the context of OI/POTS if you take on too much water as you detox and need to go pee in the night
• Worsens BACNE (spots on your back, as the toxins try to escape through the skin when you 'force the issue')
• Cost (£40 per session)
* They tell you not to do anything that stimulates the sympathetic nervous system. I am (or was) a sports addict and hadn't played sport in quite a while as my health had been deteriorating so I was really missing my tennis (as I am atm!). I decided to go to my tennis club and attempt social tennis not once, but twice in the same week, when I had only just commenced doing PT properly/regularly and with a practitioner
Needless to say my body didn't like it, exercise that would normally leave me feeling all beat up for a few days totally floored me - I had my first full blown PENE relapse and was bedbound for the first time (outside of bouts of acute viral infection and salmonella) in my life for about a week
From a theoretical perspective: if the improvements described are attributable to PT then it's also fair to say that it may be part lymph drainage improvement, part inadvertent improved neuromuscular tension ~ reduced neural sensitisation