I'm really curious about this as well. I've been learning ASL over the last month, and not being able to speak has really fast tracked my ability to pick it up, since I'm always trying to sign what I want to say instead of actually speaking. I just wish more people knew sign language. It would make life much easier. I'm actually really enjoying the whole not speaking thing. I could easily go 2 months or more of complete silence if I wanted to.
While I was at Yeson, Jessie had something come up, and I was working with another one of their staff members who knows some English, can't remember her name though. She was telling me that if I could stay silent for 2 months that would be ideal. I later emailed Jessie about it, asking if it would be better to stay silent for the entire 2 months, or if it would be better to start speaking a little bit starting after a month. Her response wasn't overly helpful, basically just said I could speak if I wanted to.
At this point I think I'll likely go 5 or 6 weeks of complete silence instead of just 4. I haven't been the best during the recovery period at avoiding coughing, and I choked on some water last weekend (I was 3 weeks post-op at that point), which made things a bit sore for a couple hours afterwords. It was just minor soreness though, so I doubt I did any major damage, likely just irritated it a bit. I figure giving it an extra week or two might not be a bad idea.