Because of their narrow opening, it's quite difficult to clean bottles to one's satisfaction. Also, if you're one of those collectors who are interested in collecting old bottles of different sizes and shapes with a view to displaying them, cleaning the bottles thoroughly becomes very crucial. Listed below are some interesting ways in which you can clean the old bottles.
Soak in hot water. Fill moderately hot water in a plastic basin and soak all the bottles which you intend to clean. Don't make the water too hot, since some of the bottles with fragile glass could break. By soaking the bottles in water, you should be able to loosen the superficial dust and grime which has adhered to the glass over a long period of time. You can also add some liquid detergent into the water to make a soapy solution and after soaking the bottles for a couple of hours or so, scrub the dirt and grime away with a soft plastic brush.
Cleaning the insides with sand. Fill the bottles with fine sand, mixed with some liquid detergent. Fill the sand and detergent mixture till a quarter of the bottle and then top it up completely to the brim with water. Close the bottle and shake it vigorously so that the entire mixture fully covers the entire inside surface of the bottle. After about 10 minutes of thorough shaking, empty the mixture and rinse the bottle with clean water.
Using brown rice. Mix 1-2 teaspoons of brown rice (depending on the height of the bottle) with some liquid soap. Pour the mixture onto the bottle and fill with enough water to touch the half-way mark of the bottle. Again, shake and swirl the bottle vigorously, allowing the mixture to reach all parts of the bottle, including the neck. Pour out the mixture and then rinse with clean water.
Using ice and salt. Crush the ice and mix some salt to it. Spoon the mixture into the bottle, close the lid and then shake the bottle thoroughly to allow the mixture coat the insides of the glass. Once done, remove the mixture and rinse with cold water.
Eggshells. Instead of throwing out the eggshells, crush them into a coarse powder, add some liquid soap and top it up with water. Shake thoroughly, then pour out the contents and rinse with clean water.
Normal method for cleaning. If the bottle is not too caked with old dust and grime and the opening is wide enough, use a bottle brush with any mild liquid detergent and warm water to clean out the bottle.
Follow the simple instructions listed above to clean old bottles and make them look sparkling and shiny, almost as good as new!!