I have bought a chandelier or two (or ten) in my lifetime. Rarely do I get my hands on them and they are clean. Usually the fixtures I stumble upon on Craigslist or in a thrift shop have been sitting in an attic for decades and are covered in dust and sometimes very old bugs. Gross. Not to fear - with a little bit of elbow grease and a LOT of glass cleaner, you can get even the grimiest of chandeliers sparkling once again - just like it did in it's glory days.
The easiest way to clean a chandelier is to take it apart (if you can). Make sure to keep track of what parts go where. Also, try to make sure you disassemble the pieces on a soft surface just in case one of the crystals fall.
Once disassembled, place the glass strands and crystals onto paper towels and heavily spray them with glass cleaner (I used Windex). Once fully covered, gently rub the strands with another paper towel. I have found it helps to grab one end of the strand with a paper towel, and pull down to wipe off the entire strand. Please note, the chandeliers I have used glass cleaner on were not heirloom type chandeliers. If you have a fine antique fixture or true crystal chandelier, please consult with a professional before using any chemicals.
You will be amazed at what kind of dust and debris will wipe off those pretty crystals! I also ended up spray-painting this chandelier to tone down the 90s brass - taking off the crystals to clean them makes painting the metal a breeze.
This thing has so much sparkle! If you see an old, dusty, brass chandelier in a thrift store, don't be scared off! Almost anything can be brought back to life with a little love and time.
If your chandelier is already installed, the best method I had found is to put a towel underneath the fixture, and spray glass cleaner directly onto the crystals. Then, wipe down the chandelier strand by strand being careful not to yank too hard. The towel will absorb excess cleaner. I usually end up doing a deep cleaning about once a year.