Most kettles can just be wiped out with a paper towel or rag. Never submerge or use harsh chemicals in a kettle cleaning.
The tempered glass, steel, etc are easy to wipe down and we recommend a simple vinegar and water solution to keep things fresh and not transfer chemical tastes to your popcorn.
DO NOT put your Whirley Pop in the dishwasher. Please hand clean with a mild detergent to keep the finish on the base.