bake don't boil sand
Just thought I'd share my experience with sand, from running a huge terrarium for a few years. I know for lizards, crabs and such, playsand or any high quality sand is preferable so it's low in sharp crystals that would damage sensitive critters.
You can place sand in a big baking bin - I guess a huge aluminium container could do. Stick it in the oven, 400F I believe for a half hour to an hour. The idea is to kill off all bacteria. Just keep in mind sand is an excellent heat captor. It takes a long time to reach a hot core temp but then stays there for a long time. The container will be piping hot for a good while before it can be handled; just turn the oven off.
Been doing this for years myself; never had any problems. Of course I could just have been lucky, but the sand was standard playsand from the hardware store. I did notice a 'mini-cycle' every time I did this - about once a year.