As I mentioned on previous page, I have sewn these quilts for Project Linus.
As I understand it, the weight induces sensory brain waves which calm children. While the commercial blankets are expensive and are sometimes stuffed with beads, our blankets were simply sewn from heavier fabrics and rolled up sheets within the tubes, making the blankets completely washable. If an autistic child ripped them open, nothing would happen other than the sheets would probably be removed. The pellets might be a safety issue depending upon the child in question. Our old sheets were donated by hospitals (of course sterilized) so again the cost was minimal. One cannot imagine the grateful comments received by families of autistic children.