Six hours all in one day means that the students won't have time to forget anything, but also won't be able to re-read the notes or study/practice out of class. In this format you probably want to give them extra material at the end which you don't cover in class, but which does include the cookbook-type material you say they'd be interested in; during class you focus on teaching theory and applying it to small cases.

One hour a week for six weeks has different problems -- even though there will be plenty of time for them to reread notes and practice out of class, the first 10 minutes of each class will have to be spent recapping what was done last week, and the last 10 minutes spent describing the work they should do out of class. However, because they can apply and test their learning as they go along they are likely to get more out of the 30-45 minutes of 'productive' class time.

My preffered format would be 3 or 4 one-and-a-half to two hour classes spread out over one or two weeks, however the formats and timetables of such classes are rarely under the teachers control enough to allow such customisation.

I would certainly reccommend that the cookbook "Code to Make PopUp Windows"-type material, even if it's discussed in class, is left until near the end and possibly simply provided as sample code / exercise-for-the-student material at the end of the course. The students if they're interested in this will be willing and able to learn it themselves once you've provided the foundation in your classes (hoom... starting to sound like another of my posts.