Wheni had my bps on cypress and aspen i would sometimes pull out bigger pieces with a tweezer. But it was just bc i felt like it, not necessary at all lol. I have them on sani chips now and sometimes quite a bit of them stick to the f/t rats. Its no biggy. I suggest not putting down paper or paper towels because if that gets stuck to the rodent and they ingest the paper it will be very bad and could cause impaction.
Ingesting paper towel= bad news
Ingesting bark= no big deal