Make ice machine cleaning solution with vinegar, lemon juice and water or pouring ammonium into a spray bottle. There are also some commercial cleaners that work well that are usually listed in the instruction manual that comes with the appliance.
To make a vinegar solution to clean an ice machine, mix 2 tablespoons of lemon juice and 2 cups of white vinegar in 1 cup of water. Pour the mixture into a spray bottle, and mix it thoroughly. If the ice machine is of commercial grade or portable, turn it off before spraying it with the vinegar. If it is a refrigerator ice machine, turn off the ice-making part of the appliance by pulling up on the rod. Pour hot water into the ice maker to melt any frozen chunks and remove the ice tray.
Spray the inside of the ice machine with the vinegar solution. Allow the solution to sit for at least five minutes before wiping it down. Rinse everything with warm water. Discard the ice the first two times after the ice machine is cleaned.
If you want to use something stronger than vinegar for the cleaning, avoid bleach because it can cause corrosion. Use quaternary ammonium instead.