With a BP, either will really work but if you do feed live, then yeah I probably wouldn't do it in the cage as like said earlier, they poop and pee all over. Of course I don't advocate feeding live as if you have ever seen what a scared to death rat can do, you will cringe, especially a medium sized one. I just pre kill as its safer and in that case, there is no pee or poop. Now like I said, if you are talking about a big snake like a retic, burm or large boas like suri, Peruvian or Colombian girl, I would advise against a feeding tub as like I said, if a 8-14ft hungry snake grabs you, you can be in serious trouble. My 5ft red tail boa girl sometimes likes to "stretch" and will wrap around my arm and flex her muscles and oh man its strong and that's just her playing around and only being a 5ft baby. But with a BP, whatever works for you.