I just used spike balls mostly since each ball can hit the EOW 5 times; for 18ish damage; you can just dig a hole and fill it with them and wait for him to stop by.
I spawn up a small world dig down, smash some shadow orbs fight the EOW a few times and sell all the muskets I get.
Usually gets me 15-20 gold if I sell the Demonite considering hes so easy to kill.