New and used bottles need to be cleaned thoroughly before sanitizing. The first time a bottle is used it should be soaked in a cleaning solution, and scrubbed inside and out with a nylon bottle brush and Brewferm Oxi Cleaning Solution available here...
A thorough cleaning is needed to ensure that there are no deposits where bacteria can hide. This helps the sanitizing solution reach all areas. If you are diligent in rinsing your bottles promptly and thoroughly after each use with your homebrew, only the sanitizing treatment will be necessary before each use in the future. By maintaining clean equipment you will save yourself a lot of work.
After the bottles have been cleaned with a brush, soak them in sanitizing solution or use the dishwasher with the heat cycle on to sanitize them. If you use bleach solution to sanitize, allow the bottles to drain upside down on a rack, or rinse them with boiled water. Do not rinse them out with tap water unless it has been boiled first. Rinsing with unboiled tap water is a number one cause of spoiled batches. Also sanitize the priming container, siphon unit, stirring spoon, and bottle caps. But don't boil or bake the bottle caps, as this may ruin the gaskets.
For more information, please check the website at www.brewferm.com for hints and tips on not only the cleaning process, but for other brewing tips as well.