There is this Russian device which is very high tech, it’s the same guy that invented the tens machine but has evolved ever further the tech what he called now Scenar, then Cosmodic and finally ENS, I own an ENS device and I remember the first few times I would get the next day the same symptoms as the person was treated.
It was advisable to always wash your hands with cold water for a few seconds after treatments to get rid of any energetic residue, learned my lesson. By the way the newer devices have a built in mirror mechanism to counteract these problems since they were common with earlier versions.
So yes healing does have his down sides too, one just needs to be aware in how to best protect themselves.