I know this is a very old thread, but for anyone reading this for reference I?ll put in my two cents.
I had been using heroin for a few weeks and decided to quit with the use of codeine at first and then subutex later. I came off the heroin and when WDs started I took codeine - two doses of 420mg a day - morning and evening, for two days. On the third day I waited until 11.30am to take a similar dose. I wasn?t feeling brilliant by about 4pm so took the plunge with the sub, taking 3x2mg over the course of a couple of hours. I didn?t go into precipitated WDs and felt better.
I wouldn?t say I was in full WDs at all by the time I took the sub but I?m guessing that the codeine wore off to the point that I was uncomfortable because of a reasonably considerable habit/tolerance.
Anyway, just wanted to put that one forward, but wouldn?t necessarily advise it and possibly I got lucky to avoid precipitated WDs. Best to wait as long as possible I?d say.