The other day I found one of my plants in a terrible condition.
I contacted a plant friend for advise and he sent me the following instructions–
Unpot the plant, clean all soil off of roots.
Mix a solution of 1 cup of water, add 1/3 cup 70% isopropyl alcohol, add 1 teaspoon of soap (Dr. Bronner’s Peppermint castile soap). Mix well
Immerse plant for 10 minutes, then rinse well with tap water.
Repot in a clean pot with fresh mix.
Wait one week then water with dilute general purpose fertilizer.
Water once a week Spring through fall, Once every two weeks winter