"OK - it's (the ER50) running with two Caps and is bubbling away!   Hooray! :o)

I Already had a reaction in one of my knees that's been bothering me (slightly posteriorly rotated Tibia bone).  It feels like I just had it adjusted at the chiropractor - but better.  Held it above the open end of the pipe and cupped my hands around the pipe to let the gas go into the back of my knee/leg for about 10 minutes. 

I've now got less pain with movement.  About 1/2 hour later, it felt good walking up the stairs and when I got to the top, the knee joint "cracked" once as I stopped walking.  Then as I pivoted while starting to walk, it "cracked" twice and it feels very relaxed - and different in a good way - like the joint just released a bunch of tension. 

This is consonant with your musings about hydration and muscular relaxation that occurs.

Great stuff!   :o)"

~ ewunder