I use a variety of substrates, I even mix some!
For snakes I use newspaper, paper towel and Beta Chip. I like newspaper and paper towel because they are inexpensive and easy to use. I also like Beta Chip because it is harmless when ingested in small amounts, easy to clean and the snakes love to burrow in it.
What I find works most effectively if you feed your snake in its enclosure is using half paper towel/newspaper and half Beta Chip. By doing this the snake gets the chance to burrow in the Beta Chip and feed safely on the paper towel/newspaper.
Beta Chip is made out of 100% virgin hardwood chips and is aspirated to remove dust. There are no extremely small particles in it. It is inexpensive (around $9.00 for or 2.5 cubic feet)but the downfall is that it is only place in Ontario carries it that I know of (Ren's Pet Depot in Oakville). If you don't live in Ontario you can order it directly from the manufacturer in the states or possibly even from Ren's....?
Here is a link to more informayion on this product: http://<br />
Hope this helps! Sean