on the DSM (drop in bobbin) I'll brush out fuzz without taking off plate, etc each bobbin change. I take it all apart and brush ("chip" paint brushes do a nice job on latching onto any fuzz) out all nooks and crannies and put A drop of oil on the wick at the bottom of the bobbin area, maybe on the main needle rod if I clean it too. My machine is built so I'm not suppose to oil it between maintenance check-ups but I do use this little amount of oil at the end of about every big project. Since I sew daily and switch around projects this is not done on a set schedule. More often if using flannel, etc.
On the long arm I will brush out fuzz each time I replace a bobbin (big ones) and pull the plate about once per month. If I'm using linty fabrics or a cotton thread I will also use canned air to get the bobbin area clean once finished with quilt. The Long arm I oil about every 8 hrs of use(whole machine) and bobbin area each bobbin.