Been using one for several years now on stairs WITH BOTH extension poles.
I use the gray brushes and towel off, sometimes on grots, I will extract after.
I use one pole at a time, the longer one to clean the riser going up, standing upright.
At the top, I remove it and replace with the shorter pole, stand two steps under the one I'm cleaning, and work my way down cleaning the treads.
Sure is a great back saver.
I keep both my Cyclo's and both Makitas in these plastic boxes as shown.
Oops, all four tools are kept in four boxes the same as the top box.
The bottom box is my spotting kit from Vac-A-Way.