Well, it's bad form to reply to one's own post, but I will anyway. I tackled these drains this past weekend. The key to my success was realizing that you can take the drain tubes off the small funnels at the corner of the windshield, tilt them forward, and get a much better angle and access for cleaning.

The battery side one is a piece of cake once you take the battery out and pull the ECU cover/shield out. The tube which leads the water through the floor of that section is reasonably flexible and you can pull it down and away from the "funnel" and stick your shop vac right on that tube opening and use your hand or some tape to help seal it. I did that, after I had poked just about anything I could fit down that tube and worked it for a while. Then I heard a big "fooomp" and the vac pulled a big clog out of there. Yes!

On the driver's side, the access is not nearly as good. I tried taking the fuse box cover off, but it doesn't really help. I found that I could depress the drain tube downward (to unhook it from the funnel) using a screwdriver handle (didn't want to use the metal end as I was afraid I'd poke a hole or rip the tube) and eventually work it loose from the funnel. Then you can bring it forward to get better access, roto root it as best you can, then vac it. Same thing - eventually a big clog came loose and voila, free draining again. Note that there is a plastic U shaped clamp of sorts holding the drain tubes, but on mine I could bend them out of the way without breaking them and then move the tube.

Note that I did not pull either tube out of the car, only tilted the mouth forward for better access. And I had thought that these tubes drained all the way to the bottom of the car - they don't. They drain to an area on top of the inner wheel well and drip out at a level above the tire.

So it is possible to kill those bad clogs!

Rgds,
Chris W.