mmm, I don't know if you'd call it clean but I have a late-1990s ceiling fan with a feature they called "fan flick" - turn it on, it comes on at the last selected speed. Want to change the speed? flick the power switch (toggle it quickly) and it changes by one notch. It's tedious, and you only get to change it one direction until it wraps around - but no wireless, no additional wiring, just "short power interruption" as a signal...