It may work at reduced saturation, but all the textbooks seem to indicate that it should be at maximum saturation. If I can dig it up, I will email you off-list with some instructions from Carl Weese for making your own K-Ox developer from oxalic acid and potassium carbonate, both of which are dirt cheap on their own. You'll need some way of measuring pH, but other than that, it is fairly straightforward. You mix it by the bucketload this way.