Cosmo Kramer of TV's "Seinfeld" successfully installed a garbage disposal in his tub, but Kramer lived alone. He didn't have to consider roommates, spouses or children who may not have had the time to wait for him to finish washing a head of lettuce.
In the real world, hair is probably the biggest issue in a shared shower relationship. For some, seeing it wrapped around a bar of soap is nothing short of dry heave-inducing. Use a washcloth and rinse off any stray hair when you're finished. Make sure there is a filter over the shower drain that can be emptied. This will prevent clogging. Follow up by spraying down the shower with a daily mildew cleaner or shower spray and you'll cut down on soap scum and water stains [sources: Apartment Therapy].
And while we're at it, make that shower quick. Nothing worse than standing in a line outside a shower stall waiting for someone to get done. Unless it's cleaning off the hair he or she left behind.