Thanks Roosterlorn, great that you got results! Experimentation is fun. So is learning from others.
So far, I found that the blades in women's razors, if you can pull them apart, are incredibly fine and sharp - seem perfect for the job. I've stored a few in a glass jar with a little methylated spirits, ready for action.
I fiddled yesterday with the foil caps and thought, well, maybe the filaments will help keep it in place, but it really didn't look secure. A little bag sounds surer.
I imagine a 45' cut creates more surface for pollen - that's a good idea. Do you mean that the cut surface ends up facing down, or up? I wonder if it would make a difference? How many seeds did you get from your crosses?