I have used them a couple of times. I use hot stones too, so it was interesting to see the difference.
The lava shells initially get really hot. I mean, too hot to hold without a towel. I had to have a wet towel nearby to
cool them off before I could really use them. As you use them the temp, equalizes, but if the shell sits still, it heats up
really hot again. It isn't like using a stone where the heat disapates and eventually cools down. The shell does cool down eventually, but not for awhile (which is nice). I primarily use them if I do not have my stones available or am seeing a client
at their home. I like them for these circumstances. I suppose if they were my only option, I would have to get used to working with the heat issue. I still love my stones.
Mary Ann is right..they do get hot..sometimes too hot to handle..I just keep a cool towel close by and use alot of palm and forearm strokes to keep the flow going in the session. There is a little rubber stopper on the shells which sometimes emits this weird squeky bubbleling sound..closest thing I can think of is the sound when the "Aliens" monsters in the movie creeps up behind you lol.. We have them as a treatment in the spa I work at but many therapists dont like them due to the heat of the shells. Clients like them as long as you keep them moving and clean up is easy. Getting them set up though may need practice. I got shells ready 10 min before my session..Some therapists had the nightmare of the shells not getting hot at all!! I guess this depends on if the reactive powder gets moisture in the packet or if it is opened too soon and left out in the air. Good luck with them..they are very beautiful to store in rooms as a nice decoration too.