If you have a plan for cleanup, why not give it a try? Nothing ventured, nothing gained. You miss 100% of the shots you don't take. Fear is the air that cowards breathe. Either way, tell us how it goes.
Using ordinary detergent will produce an insane amount of suds, which will rise and may well flood out of the soap drawer of the machine. They may also make contact with live electrics in the machine and either start a fire, or electrocute you. or both. A significant number of house fires are started by washing machines and this will greately increase the risk.
https://www.bbc.co.uk/news/business-43056887 - up to 60 fires a week in the UK caused by faulty appliances. If there's the slightest crack or gap in the flexible pipe that connects the soap drawer to the drum, then filling the whole thing with suds might well leak into the main interior, where there are exposed mains-voltage connections.
squidgyballs said: Aye, sounds a bit dicey! On another note, are washing machine pumps any good for pumping gunge or slime or would it have to be too thin to be messy?
Most modern washing machine pumps use 1-inch hoses and have a small motor attached to the pump. A person could hook the hoses to pick up and pump out gunge of some type or another. The problem would likely be the strain on the motor if the substance were to be too thick. Still, water is heavy enough, so I think these motors would run the pumps for slime or gunge if it weren't too thick.
Years ago I used to fix washing machines, so I have some understanding of these pumps. Most have an impellor inside that spins and encourages the water to move along. But a thicker substance might prove difficult, as the impellor might just spin in the substance and not move it along. I would hook up a pump/motor assembly in a water-tight container with the in and out hoses sticking out and experiment. Electricity and anything wet can be an extremely dangerous combination.
I remember one as kid putting dish washing liquid (for a sink) into the dishwasher. We had run out of dishwasher tablets and this seemed like a good substitute. If I was into soap suds I might have been overjoyed. As it was mess tat took a long time to fix.
My mom left dad at the house one time and while cleaning up the kitchen he discovered we were out of detergent for the dishwasher. Reasoning that it was the same stuff he squirted the dishwasher full of dishwashing liquid. My mother came home to find most of the kitchen submerged inside and dad was never allowed in the kitchen again which I think was his plan anyway.