Anyone used one of these? Do you find them helpful? Was looking at getting one for my 7 year old who has no diagnosis but definitely has sensory processing issues. Thought it might help calm his behavior (will maybe post more about that another time.) Have looked on Amazon though and they range from 15 pound to 75 pounds which seems a lot. Just looking to see if anyone has any recommendations or can tell me how they use them with their child or had anyone found they help with sleep, as falling off to sleep can sometimes be an issue.