I have never tried super glue on softies or shrooms because of their texture. Rubber bands can work but the little buggers like to squirm out. The best way I have found is to use a small dish in the tank out of current so it can attach without being blown away - if the current is strong you may have to cover the container with screening but I usually don't. I have a small tupperware in my tank almost all the time for this practice. It has some sand on the bottom and 6 - 8 small rocks I break with a hammer and a few softy and shroom cuttings I want to attach. For your one shroom you could use something as small as a shot glass with one little rock in the bottom. If you want to attach it to a larger rock that is part of your reef structure then use a piece of PVC 1.25" cut about 1.5" long to keep it where you want it till it attaches. You may have to adjust your current or screen it also. should be no problem - attaching in 2 - 3 days.
