Just watch your bp when he eats.
I've never had a real issue with feeding on aspen.
When I feed a juicier mouse, like a pinkie with wet skin or one that's bleeding, sometimes the bedding sticks a little. I just pick it off with my tong once my snake has struck. None of my snakes will let go once they've started to swallow.
I always offer the rodent on tongs so that there's no aspen in the initial bite.