Hi,
Horrible, horrible idea.
I tried aquarium gravel as my very first substrate back in the day.
The poop sticks to it, the pee runs through it and pools underneath.
It's very hard to clean right unless you completely remove it all and scrub the tank. It's dusty, sticks to wet mice and scuffs up their scales and makes the snake look scruffy.
I lasted 2 weeks and was swearing for most of that.
dr del