I think you are not remembering that episode in its entirety. The bathroom toothbrushes were contaminated, but so were the control toothbrushes they kept in a different location. Crap is everywhere. http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/fecal-matter-on-toothbrush/
So Google says: Perry Mason, Alicia Florrick (The Good Wife), Atticus Finch (To Kill a Mockingbird), Arnie Becker (L.A. Law), and Lawrence Preston (The Defenders).
Spoiler alert: There’s some speculation that the main character is dead and washes up on the shore of paradise in the final scene. I don’t like that interpretation, and the director seems to disagree with it, saying the end is a rebirth for the character. She was adrift emotionally in space, but in surviving the ordeal she comes back to earth literally and figuratively. She becomes grounded again. The end. http://www.vulture.com/2013/10/alfonso-cuaron-answers-your-gravity-questions.html
When I first saw the strip, I thought, oh, hell, glitch, I’ll just skip it. Then I clicked the comments bar and your comment was the one displayed. I took a moment to look at the strip and read the context and the gag became suddenly clear. I then read all the comments and saw the translation that verified I had indeed understood the strip after all. Thanks for inspiring me to try instead of being a thoughtless skimmer.
I think you are not remembering that episode in its entirety. The bathroom toothbrushes were contaminated, but so were the control toothbrushes they kept in a different location. Crap is everywhere. http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/fecal-matter-on-toothbrush/