I'm aware of a few methods (many days in the refrigerator, hours under cold water, etc.) for thawing a whole turkey before cooking it. However, I don't know how these methods balance against each other for,   Speed (do we have days or hours to thaw this turkey?), Safety (something about bacterial growth), Ease (is there a trick to this that makes it way more convenient?) ...?   What are the options? 
Restaurant supply stores carry degreaser, which will remove the brown baked on oil.  However, that oil isn't hurting your cooking at all.  It is the same thing that forms on cast iron skillets, but it isn't objectionable because you don't notice the color against the black of the cast iron.  If it works I'd continue to use it.  If you are thinking of changing, you might want to consider the cast iron Dutch Oven route.  They hold their heat better than consumer deep fryers and a Dutch oven can do more than just deep fry.  And they are easier to clean.  