A combination of vinegar, water and dishwashing liquid makes for an easy way to clean the jets on a Whirlpool bathtub or hot tub. Whirlpool jets naturally collect hair, dirt and grime over time, and due to how the jets work, cleaning them by hand is extremely difficult to do.
Fill the tub with hot water until the water level is at least 2 or 3 inches above the jet nozzles. While filling the bathtub, pour in 1 cup of white vinegar along with 2 tablespoons of dishwashing liquid. Use dishwashing liquid that is low-sudsing if possible so that the tub doesn't create a large mass of bubbles that spill out and cause a bigger mess.
After filling the tub to the proper height, turn on the jets and leave them running for at least 15 minutes. Monitor the cycle periodically to ensure that the water doesn't get low and that the detergent isn't overflowing onto the floor. Once the 15 minutes are up, drain the tub and fill it with cold water, then turn on the jets for another 10 minutes. After completing the rinsing process, drain the tub again and use a bucket or sprayer to get rid of any loose flecks of dirt or grime in the bottom of the tub.