Club soda or seltzer water can help to remove stubborn spots on gold due to their carbonation. [1] X Research source You can also use dishwashing detergent. Just make sure that it is labeled as mild. Harsh detergent can ruin your jewel. [2] X Research source
You can also place your chain into a metal strainer and then lower the strainer into the bowl until it is submerged. Then, you can remove the chain by simply lifting the strainer. This is a good method to use if you are concerned about dropping the chain. [3] X Research source
Going with a medium or hard bristled brush could make it easier for you to scratch your jewelry. It is also best to keep a brush set aside specifically for jewelry cleaning. This is on your own risk since it can spoil the jewel if it is delicate or sensitive.
One good thing about using rubbing alcohol is that it will disinfect the chain while also cleaning it.
Using ammonia as a regular jewelry cleaner can break down the pieces over time. Therefore, it is best if this method is only used on occasion and for deep-set grime and residue. [5] X Research source
Before you use an ultrasonic cleaner, it may be a good idea to talk with a jeweler to see if it is appropriate for your type of gold chain. Otherwise, it could result in damage to the chain.
You can take your gold chain to a jeweler and ask them to repair the damage and give it a thorough cleaning as well.
Also, make sure to keep your scrubbing gentle. Or, you could accidentally snag and pull a gemstone out of its setting. Some gemstones can even loose color if scrubbed too hard. [11] X Research source
If you bought your gold chain from a national jewelry chain, you might also be able to contact customer service for cleaning advice. [12] X Research source