Bill Waldrop has a new post on his blog where he talks about two of Diana's beautiful seedlings that he's in the process of converting. If I understand correctly, he dries out the plants in their pots for about two weeks first, then he moves them to his basement where he does the daily colchicine applications, then at some point he brings them into the house, and then finally out to his greenhouse where he watches them daily and does some cutting here and there to remove any new roots or shoots that might interfere with the conversions.
I love the fact that he has so many pictures of what the plants look like during the different phases of the conversion process. Michele -- I do hope you can try this within the next year, and I hope you can get some pictures too, although I can only imagine how busy you'll be if you add conversions to your already busy schedule!
I've gotten the impression that Bill Waldrop does his conversions in the cooler months, like over the winter, but I don't know that this is true -- just my impression.