Sunroof leak (continuing saga)

[meddyliol]

I have disconnected both sunroof drain tubes from the rubber things in the corners of the windscreen. The tubes themselves look dirty but not blocked. As a temporary measure I connected the bottom ends of both tubes to plastic bottles. After some rain last night I was amazed at how much water was in the bottles. Anyway, what I really want to know is, those rubber things in the corners which I believe are elbow shaped. Two questions:

1. What is connected to the other side of the elbow bend.
2. I think they are blocked so how can I clear them? Poking something in the end isn't going to do much because of the bend.

I am at a loss as to what to do apart from leaving the down tubes connected to plastic bottles. I am sick to death of sucking water off the front carpets with a carpet shampooer.

Any help would really be appreciated

Brian