I currently have two solutions for monitoring washer and dryer.
My original solution uses an Aeon HEM v1 Z-Wave device, running a ported and slightly modified driver @mike.maxwell originally wrote for SmartThings. This has worked well for many years. The driver actually generates button pushed events when either the washer or dryer finishes a cycle, which I use as triggers in RM to send notifications.
Here is the Hubitat thread...
I also have more recently installed an IoTaWatt.com whole home energy monitoring solution. I wrote an integration for Hubitat which allows me to monitor the individual circuits for the washer and the dryer. I then use RM to notify when the proper sequence of events is detected as @aaiyar mentioned above.
