If you use oven cleaner, Check to see that it is safe for Aluminum. If it is not, it will eat away the sealing surfaces and leave pits.
I would avoid the use of any metal bristle brushes on the Aluminum as they might scratch the surface. Mineral spirits and a cheap tooth brush (possibly with trimmed bristles) sound like a good combination. For the extremely stubborn small areas, brake cleaner might help.
The brake cleaner won't etch or oxidize the aluminum???