I know that last one is an XKCD reference, but no-- hitting it really hard with a rock really wouldn't
Mycelial culture is able to be replicated vegetatively. A common technique to reproduce complex fungus is to take fruiting bodies and macerate the shit out of them in a sterilized growth media. I've done it several times with fresh gourmet mushrooms to produce mycelial spawn to grow them with. (A steam cleaned, and peroxide sanitized kitchen blender is adequate most of the time. However, hydrogen peroxide kills mold hyphae. If trying to cultivate molds, peroxide is discouraged. More complex mushroom type fungus tends to have an oxidation inhibiting enzyme that counters peroxide, making them tolerant to weak first-aid grade peroxide solutions, allowing one to abuse it as an inhibitor for unwanted biota.)
drug cultivators do it all the time to cultivate psilocybe mushrooms, because producing spawn from spore prints is tedious, where vegetative culture is something even morons can do.
Anyhow- Yeah, Quaternary ammonium compounds are pretty toxic to basically anything with a cellular structure. Not as stable as copper ions for long term biotoxicity, but meh. The things that could break the stuff down cant penetrate deep into the wood's surface, so it will stick around in there. But you will have to basically soak the stuff.
and yeah, it's cheap. You can get the stuff in many off branded santizing sprays if you dont want the name brand, but the name brand does seem to have some added silicate compounds added, likely to retard gas exchanges in the wood after application.