fill tub with hot water & 1 qt - 1 gallon vinegar(depending on size of it) turn it on let run about 5-10 minutes, drain, rinse
Fill tub with hot water to cover jets. Add the powder from one dishwasher tablet or 2 tablespoons of dishwasher powder (if you don’t have the tablet kind). Run the jets for 10 minutes. Drain and fill again with cool water and run for 10 minutes again. Drain and wipe inside of tub clean.
For years I have filled my tub with water and run a cup of Clorox through them. Then rinse the tub and fill again and run the jets again with clean water.