Personally I use paper towel for substrate. 100% safer. I have had my snake ingest the shaving bedding before its not a pretty site. IT wasnt to bad but there are stories of peoples snakes choking and them sticking their fingers down their mouth to get it out. Also with the shavings I couldnt see snake poop that easily and they just got smelly. Now with paper towel it is so easy to clean the tubs.
just my 2 cents
-reptiliachnids