I got mine a few weeks ago, first one I have owned. After each use I filter the oil back into the bottle, wipe out the removable compartment from the fryer an then wash it before putting it all back. To be honest its a sodding faff
Nitromors, painted on to any built up clag, and Mr Muscle oven cleaner on any black scorching,or fill with water, add some biological washing powder and boil it. Beware the mixture will boil over so watch it.
Caustic soda solution does the trick but oven cleaner spray works well especially if the parts are warm. At work we use a product called Smoke Clean which I think is a potassium chloride solution or Lye by another name, this works like magic.