How do I properly clean the plug-in surface units?

Do not attempt to clean plug-in surface units in a dishwasher, do not immerse them in liquids of any kind, and do not attempt to clean them in the self-cleaning oven. Spatters and spills burn away when the coils are heated — after cooking, remove utensils and heat soiled units at HI for about a minute, then switch to OFF. Avoid getting cleaning materials on the coils, and wipe off any cleaning materials with a damp paper towel before heating the surface unit. (Page 28)