"This toilet is of the standard zero-gravity type. Depending on requirements, system A and/or system B can be used, details of which are clearly marked in the toilet compartment. When operating system A, depress lever and a plastic dalkron eliminator will be dispensed through the slot immediately underneath. When you have fastened the adhesive lip, attach connection marked by the large “X” outlet hose. Twist the silver coloured ring one inch below the connection point until you feel it lock."That's just the first step. The "adhesive lip" sounds uncomfortable to say the least.
Incidentally, elsewhere, someone has explained how the three seashells must work in Demolition Man (probably not safe for work - contains graphic line drawings).