I admit I dont use them on every eel I use but If I'm running low, I'll stick one on. I figured this out one day when I noticed that the hole that the hook made through the eels head was starting to stretch out. Then after 2 more casts the eel was lost. I know it sounds wierd putting a little plastic tab on your hook, but it acts as a stopper when it pushes up agianst the barb. I'd go so far and say that by using those tabs, you can use 1 eel all night-
I have an old 9' Harnell blank thats just waiting to be wrapped for my eel pole.