Be sure to clean the lint screen completely before drying each load of clothing. Clothes will dry faster, and you’ll save energy. Excessive lint buildups also can be a fire hazard.
For this reason, periodically remove lint from the vent passages inside the dryer with a brush and a vacuum cleaner. They’re usually located below or behind the tumble chamber; you may have to remove the front, rear or top panels — perhaps even all three. Unplug the dryer before doing so. If this sounds too complex, it’s better to hire an appliance technician to do the job.
Fabric softener sheets have been shown in some cases to cause buildup on the lint screen blocking airflow. Clean lint screens periodically with a brush and soap and water to prevent blockage.
To remove spots, spray the enameled surfaces with an all-purpose household cleaning product and wipe dry with a soft cloth. Dyes from clothing may be removed (or at least bleached out) with a hydrogen peroxide or chlorine bleach product (test first and rinse well). Avoid using abrasive pads or scouring cleansers, which can scratch the surface and make it that much harder to keep clean in the future.
Reference:
Jeff Bredenberg, editor, in Clean It Fast, Clean It Right: The Ultimate Guide to Making Everything You Own Sparkle & Shine.