hi,
I never did, because, when I wanted b&w, I just used the type of film and developer, that I wanted for a certain look. like ulf said, have a look on ebay and get some 120 backs, you can get them for € 70,- or less, especially the older non pro IIs. or rent them for the job, b&w film is a lot cheaper, than colour negative or slides. and if 320 ASA is ok for you, TriX should still be available in 220.
best regards,
marcel