This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
A good comb cleaner that does the work easily and quickly can be made from a worn-out varnish brush. The brush selected should not be over 2 in. wide; i t should be thoroughly cleaned with benzine and the bristles cut to a bevel, as shown in the sketch. In use, brush across the comb parallel with the teeth, and the dirt between them will be easily removed. - Contributed by John V. Loeffler, Evans-ville, Ind.