I voted frozen only, although I do thaw and warm them up first.
I too, on rare occasions, will use a live pinky or fuzzy, if all other tricks have failed. I will not however feed live, if the rodent is large enough to defend it's self. That means pretty much anything larger then a hopper is to be off'd first.
I love this part
...
The Live Pile...for those who haven't seen what a rat can do to an adult Boa or two.
Now don't get me wrong, I fed nothing but live for more then 20 years. I've made the mistake of not supervising the entire feeding, and I've had some snakes messed up because of it. I just thought that's the way it was, that they needed live prey.
Then when I heard of the F/T routine, I tried it out. And not a single one of my snakes refused to switch. I've fed F/T rodents to WC rattlers, desert kings, gophers, even a coachwhip. Not long term captives either, but local removals that wintered with me.
So, IMO, there is no GOOD reason NOT to feed them F/T. That's what is the safest for the animal. Unless you make your animals your secondary concerns.