I feed in a separate enclosure. I've been told by a number of experienced members here that that's not necessary. The other day, I asked a friend of mine that has been working with all sorts of snakes for about 16 years if it was true that the whole food association thing was really a myth. With no uncertainty he said he's worked with alot of different snakes and its definately not a myth. He went on to say, however, that his experience with BP's is that they're just so docile that he hasn't ever seen it lead to trouble. So, in the end he felt it was a rule that could be broken for BP's.
One thing I think is that people often misunderstand the reasoning behind the practice. I don't think its so much that the snake will associate your hand for food or associate its cage with food. This is where you get the counter-arguments like "Since you don't feed every time you put your hand in there the snake won't associate the two". I think the important thing that the practice accomplishes is that it trains the snake never to expect food inside its enclosure under any circumstances. For example, my snake does not ever exhibit any aggressiveness or tendency towards feeding response inside his cage even on feeding day.
About a week ago I decided to go ahead and give in-cage feeding a try. One thing that was very amusing is that as soon as my snake smelled mouse inside his enclosure he freaked out and went and packed himself as far back into his hide as he could. He continued to hide for about 15 minutes after I introduced the mouse. Eventually he relaxed and fed.
My notes on in-cage feeding:
1) The whole procedure took way longer due to the fact that the mouse had more comfortable area to hang out in and my BP insisted on waiting until he strolled right by the hide.
2) There was clearly a reaction to a rule that just been broken. I got the strong impression that my BP relied on the fact that only it and myself ever entered the enclosure.
3) In the 48 hours following the feed there was a definate change in behavior. I noticed alot of sniffing around and an increased jumpiness. It looked to me like his cage had become an exciting new world of possibilities. It was also apparent to me that he could still smell the mouse and that finding another one was the possibility he was interested in.
For me, I think I'll pass. Out of cage feeding is reliable, clean, and quick (for me). Plus, feeding in-enclosure just didn't leave me with a good feeling. I think I *could* do it and not run into any trouble. But, I also believe that there most definately is a behavior difference between the two approaches that is worth considering.
Some may say I'm drawing alot of conclusions off of one trial and that's true. But, I know my snake really well and am confident that I got a pretty accurate impression of things.