Let me tell you that whether sand has a legit purpose as far as drying goes I don’t know, but I would much rather move around in sand than over rocks. Sand is a wonderful crawl space addition if you ever have to do work down there. \
Your knees will thank you. \
Well, we have talked about a few points. All the way from opening the space to let it dry, to digging the foundation to use perf pipe. \
The point is, moisture doesn’t have to be your nemesis. It can just be another maintenance point for your home. One that's well regulated either by a sump pump, a dehumidifier, or a moisture barrier. In some cases, maybe all three. Still, it's within the wheelhouse of “doable” by you or your favorite professional. \
Happy DIYing! \