Is there any quicker way of cleaning up old brass than rubbing it with brass polish? I have an antique solid brass cabinet knob which has spent serious time outside in the Irish climate (the house itself is pre-1830s so the knob is probably an original feature, which would make it around the same age). We found a lot stuff semi-buried behind an old stone wall out back, and I want to clean this up and use it for a paperweight.

Trouble is, I've spent ages going over it with Brasso, and it does some good, but the dark gunge is stubbornly sticking over a lot of the surface while other bits are now shiny, giving it a peculiar mottled look which Michael likes but I hate.

Is there a faster, less arm-aching way? Any handy household-hints? Bicarb of soda, lemon, vinegar, boiling...? I've scrubbed it in cool water with a decommissioned toothbrush and washing-up liquid, which has taken the surface dirt off, but the serious layer still remains in blobby patches. The brass isn't really pitted (or not much) and it is solid, not plated. Any magic solutions out there, or is it just a case of elbow-grease? Thanks!

Bonnie