I like enemas in the shower but like to start lying on the shower floor with my feet on the built-in seat to start. then I can pivot so my legs are straight up on the side, over the grip rail. this way I can take the most amount of water before expelling. and the first expulsion is very forceful and a shower of sorts....only done after the output is pretty clean, though...but to get it all out, I go back to the original position. moving from lying down with a full load to standing up really adds pressure which is quite pleasing but hard to hold,,,,,good thing I exercise my sphincter a lot, its fun to hold on as long as possible, but I must stay in the shower until im all cleaned out. have not tried the rubber sheet approach but it sounds interesting. I used to have rubber shorts which I would wear to help hold the enema in, and that was a lot of fun. expelling into the tight rubber shorts was exciting, and usually wound up with play time. too risky to leave the shower with my rubber pants full, although I would like to.