Oh, yeah...I've had to do it too..plenty of times. Especially with western snakes. Even if you end up having to feed it lizards for years, it's a helluva sight better than letting it starve or having to FF every meal. Just try getting a Coral Snake to eat mice, or even dead lizards. I've had to spend entire weekends doing nothing but looking for feeder snakes and lizards (of course, if you happen to find a Scarlet King or a Brooksi or something in the process, that's a bonus). Sometimes you just have to feed them what they will eat if you want to keep them.
I've just seen too many people give up early on neonate colubrids, like Gray Bands and go ahead and give them a Sceloporus to get them to eat, then find that they can never get them switched over.