We bought a 70 year old house which has a lot of beautiful wood doors and trim. The trim and baseboards are very dark. I don't know if this is from years of dirt, or if the varnish has gotten darker, or a combination of both. Anyway, one day I tried using a little bit of Comet scouring powder on a damp sponge and the deep red tones of the wood came through. Again, I don't know if I just took a layer of dirt off, or a layer of varnish as well. Anyway, I don't think a scouring powder is the best thing to use on wood throughout the house...any ideas???