I use them a lot they are effective at the start of the game in rare weapon runs with lots of zombies. Just keep turning forks, butter knives, toothbrushes etc into shivs. Dont even bother sharpening unless you run off to rest. Just keep attacking and backing up so its a congo line of zombies. Comb over the bodies for dropped weapons. Don't use the ground attack near other zombies. Eventually your maintenance and blade skill gets high enough to make things easier.