I ride 50+ miles a week, EVERY week. My wheels come off once or twice a week for a wipe off and to check the belt for worn teeth, this happens anytime I hear or feel something odd. Squeaking, taping, clicking, etc. Wheel bearings get fully soapy washed out and re-lubed once a month, along with trucks, bushings, hardware, and risers.
I got the cir-clip tool so I could take the motor apart and wipe off the bearings. I have about 400 miles on my new motor and I’ve done this twice. Inside the can I use a toothbrush to pull the dust on the magnets to the edge, and remove with loops of masking tape. There’s a lot of magnetic dust on my commute, compressed air won’t work well for me because there’s no place i can blow the motor out and not pick it all back up later on.