Now, Bob was a Deity, and no matter how hard they tried, it wasn't easy to forcefully keep his mouth shut. The alternative that the crew found most effective was to simply keep his mouth busy, so that he would not be able to use it to talk.
Some routine ways in which they did that was through the use of jawbreakers, or basically any kind of food, making him blow bubbles, a silence competition, playing breath based musical instruments and telling him that silence was golden.
On rare occasions, they froze the space around his lips, forcing them shut, or threw him into an illusionscape where he thought he was speaking, or maybe, if they were feeling especially bold, ask him questions to which he couldn't possibly respond with something absurd.
