Get a small glad ware container from the store drill a truck load of holes into it drop in what you want it to stick to (corse sand, small LR peices, frag disc etc.) then toss the shroom in and cover with bridal mesh or panty hose hold it down with rubber band. Every three to four days check it and clean out container until it sticks.
I do this when I prop my shrooms , rics and it works great. but, somtimes it decides to stick to the contianer it's self rather then the rock at this point peel it off and try agian. or cut the container with shroom attached and mount to the rock sooner or later it will "walk" off on it's own then pop the plastic off.
This works well for unmounted Zoa's as well.