Which substrate for Red tail Boa?

Which substrate should i use for my Red tail Boa (BCI) considering that i feed him in his tank and he swallows some of the substrate while eating?

Not a red tail but still a heavy bodied boa, I use teklad shredded aspen for my dumeril's boa and feed in tank. She always ingests a bunch and it has zero problems.

I've used everything from Eco Earth, ReptiChips, American Excelsior aspen, Zoo Med aspen, All Pet aspen, Plant It Grow IT coco husk. And personally i went back to aspen for everyone. Plant It Grow IT would be my second choice. Works well for my boas except they tend to bury their butts in it and poop or piss so trying to find a poop or piss is a challenge. Nothing quite like sinking your finger into a semi chilled pile of urate.

With all that said, i prefer aspen. It's easy to spot pisses and poops on especially for the retic and using AP cages, i dont have humidity issues. Plus it doesnt start to get a wet smell i got with all the coco stuff. AP cages hold humidity VERY well so my biggest problem was the stuff was either too wet or too dry. I couldnt get a nice happy median. With the aspen, it's easy to get 70% without overdoing it.

@redshepard- where do you get your Teklad stuff from? You order the big 7 cu ft bails?

Sauzo, I ordered those 4.38 cubic feet ones, but I don't remember the exact site anymore but you'll find a bunch googling it. My brand is Envigo, and 7093 teklad, whatever that means LOL.