No. Sand is not an acceptable substrate for snakes in general for a number of reasons.
1) Sand can become lodged in the snakes vent.
2) Sand harbours bacteria like crazy, even when you think you have accurately cleaned your enclosure, filth is often hiding in the layers.
3) Sand can become ingested whether it is your intention or not, it's has the risk of causing impaction.
4) Sand and its dust can become lodged in the nostrils and depending on the species also their heat pits, this can irritate your animals respiratory system and cause an infection in the long term.
5) When balancing cleanliness and humidity, sand simply does not work. Wet sand is unhygienic but dry sand will cause poor sheds.
Turf, newspaper, paper towel... There are plenty of alternatives to using sand in a snakes enclosure
Best of luck with your new babies!