Exactly. OP, your test and the voltage readings you quote are meaningless because you are trying to measure earth leakage, which is approximately a fixed current, using the meter's voltage range. The appliances do not 'leak voltage.' They leak current, which instead of flowing through the earthing conductor of a fraction of an ohm, is being forced to flow through your multimeter set on a voltage range which may have a resistance a milion times higher. So the voltage you read will be a million times what it would be if the earthing was connected up as normal. Suppose the washer leaks 0.75mA, a perfectly normal figure. A meter with an input resistance of 100k ohms will read 75V when inserted into a break in the earthing conductor. Reconnect without the meter leaving say just 0.25 ohms of cable, and you'll get 0.75 × 0.25 = 0.00019V.
Moral: Don't use a voltmeter to measure amps!