Nobody puts anything down for them in the wild, nobody cleans their food.
If you're really worried you can put a paper plate, cardboard, etc... down. But most snakes will just drag it to where they want to eat anyway.
THIS ..
I put a couple of pieces of card down over the Repti bark in my vivs and feed over the card .. Those card separators in boxes of chocolates / biscuits also work a 'treat'..