Radhika said, “How to clean the inside of a copper bottle which has a narrow neck?”
Cleaning
an area that you cannot reach can seem impossible, but there are some clever ways to scrub inside narrow neck bottles. Select a method below to clean your bottle. If one method doesn’t work, keep trying other methods until you find one that does. Always use a soap or cleaner that is safe for your specific bottle material.
The Brush Method
There are brushes made specifically for tall bottles like this. They are called bottle brushes and can be found wherever baby products are sold as they are often used for baby bottles. If you cannot find one that is long enough for your bottle, try searching online.
The Rice Method
Rice can be used as an abrasive for scrubbing inside items that have narrow necks. Pour some dry rice into the bottle; about 1/4 cup should be enough. Add some soap and water, then hold your hand over the spout to seal the water inside. Shake the bottle to move the rice around so that it can scrub the bottle. When finished, carefully pour out the water, then dump the rice into the trash. Rinse the bottle with soap and water to remove any remaining residue.
The Cloth Method
This method should only be done with bottles that you can stick your fingers into as the cloth will be difficult to remove otherwise. Wet a wash cloth with soapy water, then stuff it into the bottle. Shake the bottle to move the cloth around inside it. When finished, tip the bottle upside-down and pull out the cloth. If you can’t reach the cloth with your fingers, try using chopsticks.
The Bubble Method
Fill the bottle with water, then drop in a denture tablet. If the tablet is too large for the opening of the bottle, you can break it into a few pieces. Let the tablet fizz for as long as needed to clean off all of the residue inside, then rinse it out with soap and water.
Thank you so much for your reply with tips on how to clean a narrow neck bottle.
But my problem is that copper tends to turn greenish and these methods are of no help as they will not remove the green.
Radhika,
The green that you see on copper is tarnish caused by exposure to water. To remove it, you can use lemon (juice or slices) and salt. In this case, use them similarly to the Rice Method above; pour in some lemon juice and salt, hold your hand over the spout, then shake the bottle.
Hope this helps!
Source: HowToCleanStuff.net – How to Clean Copper