After draining the oil from a deep fryer, use paper towels to soak up and remove any remaining grease, and wipe away loose food residue. Use hot water and a few drops of detergent to scrub away tough stains, then fill the unit with hot water, and rinse it out.
If the fryer is cleaned shortly after use, the oil may be reusable. After allowing it to cool to around 150 degrees Fahrenheit, carefully filter the oil from the fryer through a cheesecloth-lined filter to remove bits of fried batter and food. Oil can be reused multiple times, although the smoke point is lower after repeated use. If reused oil begins to smoke, change color or smell strange, discard it and use fresh oil. Oil that has cooled to room temperature inside the fryer for an extended period of time should be discarded due to the potential for microbial contamination.
A counter-top deep fryer should not be immersed in water to prevent damage to electrical connections. Instead, fill the oil reservoir with hot water from a pitcher or container, add soap, and scrub, then pour out the liquid into the sink. Repeated wash and rinse cycles may be necessary to get out tough residue. If any oil is present on the outside of the deep fryer, it can be wiped away with a damp paper towel or sponge.