Remove primary sprocket cover-ZZR1100

OK, I've never owned a bike with a hydraulic clutch before The manual says to "remove the slave cylinder,push the piston back as far as it will go, depress the clutch lever and put a band around it (this stops the slave piston from popping out)." I just want to clean the gunk out of the primary sprocket area. Pushing the clutch lever with the slave cylinder free was the LAST thing I would normally have thought to do. Is this correct?? I don't want to pop the piston. Anyone done this, please???

I have a ZZR and depressing the lever while the slave cylinder is off would be the last bloody thing I would do!
Just put an elastic band over the Piston, if you can be bothered!
For me personally... stuff it, just let it hang