What is the fluid in an electric towel rail?

[librarian]

Apropos a discussion at work I was net searching on the subject of mediaeval foot torture; the boot and such.
Victims' feet would sometimes be basted in oil/lard prior to roasting precisely to protract the ordeal.
Jacques de Molay clearly wasn't sufficiently basted as his feet were charred to the bone resulting in his foot bones ( metatarsals ) falling to the floor.
I suggest you'll have more chance of extracting a confession from your towels if you leave the oil out.