Eliminate the "elbow grease" and get yourself one of these... from Dremel
Versa 4-Volt Cordless Lithium-Ion Max Power Scrubber Cleaning Tool Kit
for about $49.95 at Home Depot. Has a variety of easily used scrubbing pads.
For those who remember the Jim Barrett modification to the Lionel track cleaning car...this is like that on steroids.
It does a fantastic job.