note that they come in 30 amp and 100 amp and look exactly the same. make sure you get one that will read when both devices are in operation. or use two.
you can power the circuit locally and output through optocoupler. you can get optocouplers that output with a linear output and then put that into your low voltage side. the reason is to isolate high voltage from ANYTHING that anyone might ever touch.
Ah, I should've been more specific. The points where the washer soaks/stops vibrating/stops consuming power is ok. I can program around that with some watch for delays before transmitting.
I like the sound idea, that might be the most non-invasive option. It might be that vibration is too hard to catch. I think the current transformer would be my last choice, as I'm not keen on playing with high voltage.