Geberit instructions say "Sound insulation pad is optional or required." The picture shows a thin sheet of indeterminate material with the appropriate cut-outs that you mount between the toilet bowl and the wall, then trim off the excess with a knife. Sound deadening aside, it seems a good idea to me to have some sort of rubber (?) material between the bowl and the wall to increase friction and compensate for any microscopic unevenness. Otherwise, the slippery ceramic bowl is mounted directly to the slippery ceramic-tiled wall. What do you think? Should I try to fashion some sort of gasket? Out of what material? (I don't really want to order the official Geberit "sound insulation pad" and then have to wait for it to arrive.) Or should I just go ahead and mount the toilet bowl directly to the wall and trust the two bolts to hold it firm enough for it not to slide down eventually?
Thanks in advance,