Most musical instruments are made to be visually pleasing as well as audibly pleasing. This is true of the clarinet, the keys of which are often made in appealing metals such as silver for better overall aesthetics. With time, though, even the most beautiful keys can become dirty and tarnished to an extent that a simple wiping down cannot cure. In these instances, it is helpful to know the steps for fully cleaning your instrument's keys.
Clean the interior of your clarinet with a standard swab to ensure that moisture or particles from the inside of the instrument do not escape through the tone holes, creating the need to re-clean the clarinet's keys soon after the initial cleaning.
Clean the key pads. To do this, place a piece of pad-cleaning paper (available at instrument stores) between each pad and the tone hole it covers, then press the pad gently against the tone hole and pull the paper out. You may need to do this more than once if any of your instrument's pads are particularly dirty.
Lay out a large, clean, white cloth on a flat surface and lay the upper section of your clarinet on it.
Remove the keys from the clarinet section with an eyeglass screwdriver and set them on the cloth. Be careful to keep track of all the pieces you remove and exactly where they go; it may be helpful to label them. Wipe down the exposed body of the clarinet with a clean cloth to prevent any existing dirt from transferring to the keys once they are clean and reattached.
Individually wipe all sides of each key piece with a silver-polishing cloth (usually sold for kitchen utensils). Only wipe each piece enough to remove the visible dirt and tarnish, and do not wipe the cloth on the tone hole pad.
Reattach each key piece to the main body of the instrument as you finish cleaning it. This will help you keep track of which pieces you have finished and which still need cleaning. Be careful not to over-tighten the screws so as not to damage your instrument.
Apply key oil to the joints of every key piece on the section to replace the dirty oil wiped away during cleaning. Wipe away any excess key oil with a clean cloth.
Repeat this process with the lower section of the clarinet and any other silver pieces, such as the ligature and bell ring, once you have finished the upper section.
Make sure before you start that your clarinet's keys are actual silver. Some clarinets are made with nickel silver or German silver keys, and some products intended for cleaning genuine silver can damage these.