I have a Bernina, when I bought it I was told it didn't need to be oiled, and removing the cover would void the warrenty. So, when I clean it, I use a q-tip with one drop of oil on the tip. The lint clings to the oil, it gets cleaned and oiled with out voiding the warrenty. It takes several q-tips to get it clean. And I can get into the very small places to get the stray lint the brush won't reach. When I FMQ, the lint builds up fast. I check it after every bobbin. Just be carefull not to catch the cotton on anything and tear it off.