Herco Spitballs are excellent for keeping the bore of the instrument clean in between baths, along with a leadpipe swab. Used once a week, they help to break down and remove food debris etc that may have collected in the instrument. I use one spitball with all valves open, and then the same spitball with all valves depressed. DO NOT USE WITH VALVES HALF DOWN! The spitball can get jammed. Each spitball should only be used for one cleaning, else there is the risk of mould.
The spitball fires out of the bell at quite a speed so either aim into a bin or, if you prefer, at a trombone or woodwind player.