I use them but had someone more competent than me fit them....
I do know though that you don't have to drill out stuff. Where the stops go are two types of ferrules, nosed ones for stops and normal ones for mechs, end bits. If you buy the gear ones they are already cut to length and there are Campag and Shimano ends....don't use the wrong ones !!
There is a liner that goes down inside the outer and 'boots' that go on the ends to seal.