Thanks heaps I have the gel/magnetic hand devices, will give the human hand held electronic devices a try!!
this may not be what you're looking for but i have seen jelly curries with one side that's like massaging rolling balls or magnets of some sort, jelly curries are usually offly cheap as well
Buy a human hand held one. They are usually cheap.
You can try some massage gels or balms. They are not very expensive and easy to use. The only disadvantage is that you need to massage the horse yourself but I personally see it as a way to create a bond and make the horse confident.
Have a good day!