I wish I’d taken a photo of the feed dogs before scrubbing them clean because they were so packed with dust that I don’t see how they were providing any traction to move anything. Take your stiff little brush and go back and forth and in all directions until everything looks bright and metallic and sharp. (Do that before doing anything else since it sprays a lot of dust everywhere else.)
Even after an initial swabbing down with a qtip, I looked in and saw an amazing amount of dust. But now I’m all clean and oiled and purring away again.
More stiff litle brushes and elbow grease are needed in this world!