I've got a 4.5 foot male BCI and I use aspen in a big tub. I feed him in the tub. I avoid impaction by putting the rat on a paper towel. I've used that for a year and a half and no problems.

I really like aspen because if you make it deep enough then the snake can thermoregulate. Mine will move up and down the aspen depending on what he needs for digestion or whatever.

Works great.

Payton