What, exactly, is the purpose of processing Kodachrome as black and white? If you have already shot some photos you want to salvage, ok, I can understand that. But to set out to shoot it? There are designed-for-black-and-white films that are bound to be better.
I suppose "because you can" is really reason enough if you really want to do so, but that just doesn't appeal to me. Too much work for results that won't be as good as I could get with tried and tested films.
I have one roll of K200 I didn't manage to shoot before the deadline. I figured I'd just keep it as a souvenir. I shot all the 64 I had.