NASA developed a vacuum-cleaner-like toilet for the shuttle, but it was subject to frequent breakdowns, and even when working required practice to ensure that unwanted materials did not end up on the body or in the air rather than in the intended receptacle. Astronauts learned to strip naked for bathroom sessions since "It's a lot easier to wipe ---- off your skin than it is to get it off your clothes". Earlier astronauts, or current ones in the event of toilet failures, had to use plastic baggies with adhesive mouths and built-in channels for two fingers to aid in coaxing material out of the body into the bag. In any of these systems leakage inevitably occurred, with the reality of spaceflight being that "it was like two weeks spent in a men's toilet" in the word of the Gemini 7 astronauts. By the end of the mission, between errant body fluids, vomit from space sickness, and residual foodstuffs, the walls of the shuttle had become disreputable. Each crew would do a major cleanup, wiping the walls with rags, prior to reentry.