My dad used that to kill gophers. Dump some bleach then hold breath,ammonia, cover and get away before you breath again. It worked.
don’t know about gophers, but I use my dogs poo to keep the moles out of my front yard...they don’t like that smell. Make a hole in an active run and put on gloves and drop a large turd down the hole, but don’t fill the hole in with dirt. Put a rock over it. Do it every 5 feet or so...they move within a week...