^^^ I watched a doco on that about 30 years ago, the collectors would come round to empty the meter only to find a shit load of rust and 1 10 bob coin.

There was also a trick of making a loop too with some cable, knew a guy that did it and thought he'd be earthed stood on a wooden chair whilst his hands were touching metal on the meter.

Seen someone use one of them old CRT TV magnets to try and slow it down too, not sure if that worked.