Clanliness of enema equipment has always been a concern and with that in mind, here are a few thoughts. First of all, most users should realize the closed top 'combination syringe' is almost impossible to clean if contaminates are allowed to get into it especially from 'back flow'. Using bleach can be destructive to rubber and dangerous to the colon if not completely flushed away. An 'open top' syringe allows one to turn it inside out to really inspect, scrub and dry it. Also after several enemas it is a good idea to put 1/2 pint or so of 3% peroxide into the bag, tubing and tip and let it soak for 3-4 hours to kill lingering bacteria. All this assumes a through flushing after each session with hot soapy water. If you can, replace the tube connection at the bottom of the bag with an inexpensive anti-backflow device such as Optimal Health sells (2/$5) or place one in the tubing.
Now the tubing. Doing the above will help, however, as you know the tubing takes forever to dry. After shaking water drops from the tube, hold one end (clamp open) against a vacuum cleaner hose or port allowing it to suck out remaining droplets for a minute or two. Those droplets won't hurt the vac and your tubing will dry in no time. Dry tubing reduces mold growth, provides peace of mind, and will extend it's (and maybe your) lifetime.