Put enough water in the bucket to completely cover the height of the plant being dipped. Mix in the appropriate amount of insecticidal soap per label directions.
Crumple paper towels or newspaper and pack around the top of the soil to hold it in the pot. Place the pot into a plastic bag and tie it tightly around the bottom of the stem or use a twist tie.
Turn your plant upside-down and dip the foliage into the insecticide solution up to the lip of the pot. Move it around for a few seconds to make sure it is completely covered. Some aphids will fall off into the water, but they will soon die.
Remove your plant from the bag, remove the paper and place it in a semishady to shady location to dry. Do not place the plant in full sun, as this may cause leaf burn.
Repeat the procedure with any other infested potted plants. When all plants have been treated, water the plants with the remaining solution to kill any insects harboring in the soil. Place plants back into their regular spots when the foliage is completely dry.