i know it seems ive bombarded this forum today with questions on this, but i just had a thought about a diy ghr floor model. what if you took the thickest pvc you could find, cut it to about 2 feet wide, then drill a hole from one side to the other in the middle of it, slide a medium thickness pvc straight through that hole, then with that pvc going through (so it makes a T), put insulation padding around the thick pvc and then plenty of duck tape.
from here, put a hose clamp over the end of the medium sized pvc that went straight through to keep it from coming out. finally, go all the way back to the other end of the medium sized pvc, put a T connector on it and put 2 small pieces of pvc coming out from it.
now, from here, place it up against a wall. this way, your heels are pressed against the wall, your toes are pressing down on the back end of the pvc where the T connector is, and your knees/quads are resting on the thick insulated pvc portion. you can adjust the length of this ghr by sliding the thick pvc back and fort, and the hose clamp to keep it from moving forward when you go down and up.
the only thing id have to figure out is how to hold my feet down. i guess i could have my wife hold my heels, lol.
does this model make sense? basically it would look like 2 pvc pieces making a cross, 1 super thick with padding and the other skinny to go through it and up against the wall. not tge best, but prob. $30 max amd would be better than a natural ghr.