It’s not necessary for auto clean model. The blower casing and oil pan collect the most oil. If auto clean is being used as recommended, there is not need to remove parts to clean. The fan blade is coated and will repel excess oil to oil pan, and being flush out when auto clean feature is used. If you like to remove the parts to clean, we do have EZ model which is easy to take apart to clean.
We recommended turning on the hood when the stove is on because even when simmer, there are oil, Steam and odor coming out of the pot. By having the hood turn on when cooking, it will also reduce the temperature for the cooking area and will prolong the lifespan of the hood.