Guys, gotta thank you all for giving me a good laff for the day...
As for above "Dare" re 7.2V across your finger/skin/skull etc etc... yeah, done all that before in the past. Tried 14.4V too.
Dry finger... not much happens that's worth reporting.
Darn sight more "tingle-y" if you stick the contacts on your tongue though.
Here's the lowdown mateys...
Dan's Data: AVOIDING ELECTROCUTION (it may be easier than you think)
Interesting reading, will answer all your questions re electricity.
But sorry, Dan don't know much about hotting your 540!!