Here's what I did... First I used a magnet to see if they were solid brass or brass covered steel. The magnet will not stick to solid brass and WILL stick to brass coated steel. If you use this method on brass coated steel you will probably remove the tarnish AND the brass and be left with an uncoated steel object - you might not want that!
Green-ness: 5/5 for buying second hand and refurbishing with items in the kitchen cupbourds
Frugal-ness: 5/5 for getting a bain and for buying second hand!
Time cost: Not the fastest thing you will ever do - especially if you want to get every last scrap of green off the item. Maybe an hour to do all three.
Skill level: Just soaking and scrubbing - maybe detailing if you are so inclined!
Fun -ness: Great fun to see them all shiny and filled with burning candles!