There's nothing like a long, hot soak in a tub with massaging whirlpool jets after a long day of work or play. Many people like to add bath oils and salts, bubble bath and other treats to the water. Over time, soap scum and remnants of the other bath additives can accumulate in the whirlpool jets. When you turn on the jets and black flakes fly out of them and into your bath water, it's time to consider cleaning the whirlpool jets.
Turn the whirlpool jets clockwise so that there is no air induction.
Fill the tub with hot water until it covers the jets by 2 inches.
Add 2 tsp. of powdered automatic dishwasher detergent and 5 cups of white vinegar.
Turn on the whirlpool and allow it to run for 15 minutes. Turn off the whirlpool and in 30 minutes, run it again for an additional 15 minutes.
Use an old toothbrush or small, long-handled brush to scrub the plastic parts of the jets with cleanser or household bleach.
Drain the tub and fill it again with clear water. Make sure the jets are covered by 2 inches of water.
Turn the jets counter-clockwise and allow the whirpool to run for 5 minutes. Drain the tub.