As with all musical instruments, proper cleaning of the bass clarinet is a vital part of proper maintenance. This unique member of the low woodwind family is both valuable and fragile. Like all wind instruments it is prone to collecting high amounts of grime. This means that proper cleaning should be both thoroughly and carefully performed using the right tools and process.
Disassemble the instrument. It is easier to thoroughly clean a bass clarinet that is separated into its component parts, as the swab can move more easily through shorter spaces.
Swab the clarinet. Gently drop the weighted end of the swab's string through one end of each piece of the instrument and allow it to fall out the other end. Then, grip the end of the string and carefully pull the swab through the instrument--if you encounter any resistance, stop pulling and tug the swab back out the way it came, as it has likely gotten caught on something. Run the dry swab through each part of the instrument several times.
Clean the tone holes and barrel. Dampen a cotton swab with a small amount of rubbing alcohol and use this to swab the tone holes and inside of the barrel to remove any encrusted grime. If the instrument is particularly dirty, you may need to go through several swabs.
Clear the pads of grime and moisture using cleaning papers. After any alcohol used to clean the tone holes has dried, place a sheet of cleaning paper between each pad and the hole beneath it. Let the pad close, then pull the paper out slowly. Repeat until each pad moves without sticking or making noise.
Polish the metal components. Smooth away any fingerprints or smudges from the metal workings and bell of the bass clarinet with fingertip pressure behind a soft instrument polishing cloth. For best results, use small, circular motions.
Scrub the mouthpiece. Remove both reed and ligature from the mouthpiece and wash it with dish soap and water, scrubbing with either a mouthpiece brush or an old, clean toothbrush. Scrub gently, then rinse thoroughly with water and air or towel dry.