It works without any major problems. Just develop the film as if it were a black-and-white film of the same speed. Ultimately, the only question is: what’s the point? If you just want to scan the negatives, this isn’t a bad option – the films are dirt cheap, especially at chemists, the developer isn’t expensive either, and whilst the grain and detail aren’t exactly spectacular, they’re decent enough. The only problem is the failure to remove the film layers and colour couplers not required in the black-and-white process, and so on; combined with the orange mask of colour films that cannot be removed, the negative turns out very dark. This means that it’s almost impossible to produce high-contrast black-and-white prints from these negatives, as black-and-white photographic paper is blue-sensitive by default and the orange mask acts almost like a protective filter.
If you only want to scan the negatives, you might as well have them developed in C41 straight away; it doesn’t cost much, preserves the colour information and can be converted to black and white after scanning. If you want to enlarge black and white prints by hand, it’s better to use black and white film – it’ll save you a lot of hassle later on. The price difference between the films isn’t worth the stress in the end.
There’s a Flickr community on the subject here:
http://www.flickr.com/groups/c41inbw/
Best regards,
Peter.