they way i have found to be most effective for fraging mushrooms is to cut the "cap off and then split that into 4 even "pie" pieces and then let them attach to rocks themselves. if done right you get 5 out of one because the basal disk grows a new "cap".
I have mushrooms all over the place, and I am constantly seeing little ones pop up. I am currently trying to physically remove them which is hard cause if you do not get it all, the piece will just float away and become a new mushroom. They are a nuisance in my new tank I inherited, and all I really have are, mushrooms, buttons and some type of Xenia I have not found out what it is yet. I will be postiung pictures next week with everything I need identified, by the experts since I am so new.