UPDATE. Probably used caustic soda. Never ever use caustic soda in a washing machine of any make.
The reaction with aluminium goes like this: 2Al +2NaOH + 2H2O = 2NaAl02 + 3 H2 (h2 being hydrogen gas as a by-product = if smoking a Woodbine nearby = a potential embarrassing Large Bang = no more machine = no more washed underpants or much worse! Apart from the destruction of the Aluminium alloy spider!