@norenlaw, that sounds like a good use for the HS300. Good chance that none of those would have single unique on and off signatures. Most consumer electronics give Sense two difficulties. 1) Power supplies hid the real usage inside the device by spreading it out over time and 2) most have usage that is highly variable based on content / activity… See my experiments with my TV - not so useful even if Sense could detect an on and an off-signature, since most of the variability depends on content when it is on.
My take is that modern washers with electronic controls won’t be detected by Sense. Too much stuff going on. Good use for a traveller or a permanent HS110.
Sense does seem to detect the heating element of some electric dryers and perhaps the tumbling / fan motors.