Healing sands?

Do you believe Chennai's beach sands have healing properties. Many do... and not just the morning walkers. People in the local areas with children suffering from nervous or muscle disorders believe the sands can heal. They bury the kids hip-deep in the sand and pour water around them to pack the sand tight. A session seems to last for about 15-20 minutes. This is supposed to help strengthen the bones and muscles.
I don't know if it cures the kids but they certainly seem to enjoy it.