I just got my ball python 2 weeks ago. i just got him to eat a f/t mouse, however while swallowing it, not only did he eat it backwards, but he got some substrate stuck in his mouth. the substrate is shredded aspen. while frantically searching for what i should do, he seems to have swallowed it. will he be alright?

Also, i've noticed a lot of people saying that you should feed them in a separate container, however since he rejected a mouse a few days back, I felt that he'd be better in the cage he was comfortable in. One thread said to put newspaper down before you feed them and take it out after, should i do this a few days before so he can get used to it?