If you don't know the best way to use these, here it is:
The brush is used totally wet (saturated with water). Dip it in distilled H2O and get it completely soaked. When you pull it out, you'll discover that the brush makes a really nice razor edge tip. That's what you are paying the money for.
Take the brush and shake it off pretty agressively onto the floor. I shake it at least once in the four orientations of the brush (flat, two sides, and on edge, two sides).
The brush should now still be quite wet but not dripping, and the bristles should form a solid edge with no gaps or seperations. If you get seperations, you need a little more water. I don't think you can shake too much water out in a few shakes, but if you do, redip, and start over.
Now you are ready to coat. Pour the solution on the paper, dip the brush in the center, and then start spreading reasonably fast. You want to get the solution evenly coated as fast as possible, because otherwise you may have problems with blotchiness in the print.
When you're done, rinse it well and dip it in some distilled water as a final rinse. Leave it sitting wet for your next coating session.