Find your foam routine.
Two methods from the directions on your Rinlo foam pack.

The aligner method
Spread a small amount of foam evenly inside your aligner tray. Wear your aligners and spit out excess foam. Follow the directions on the pack.
The brush method
Apply a small amount of foam to your toothbrush. Brush as usual and spit out excess foam. Follow the directions on the pack.
Cleaning a removed aligner
Dispense foam onto the aligner and brush gently. Rinse with running water, then keep it dry for next use, as instructed on the supplied label.
Foam and cleaning tablets have different directions. Never place a tablet or tablet-cleaning solution directly in your mouth.