I sometimes do a kind of similar trick -- take a dripping wet finger and put it on the earth of a plug socket. Of course on top of that they are shielded, I have rubber soled shoes because I don't like recharged too often and RCDs have been the standard in this country (de facto rather than enforced until about 6 years ago and seldom a hard sell before then) since before I was born. Those that have a sharp intake of breath....