You massage controls, often referred to as water diverters may get very hard to move due to sand, grit and body oils getting into the body of the diverter. If this happens it is important to turn off the spa first to protect your safety. Next unscrew the base of the diverter by twisting anti-clockwise. There is no need to remove the handle. Wipe or wash out the body of the diverter to remove the grit. If the bottom of the diverter is badly scratched use fine sandpaper to make it smooth again. You can use detergent or methylated spirits to remove any oily or sticky marks, then insert the handle or diverter mechanism and screw the base back on.