Andy Blackburn wrote:
Anybody ever run water with colored vegetable dye through
one of these to see where the fluid actually goes?

No need for dye, just use the real thing...

I've heard stories of pee getting sucked back into
the rudder bellcranks and hinges with highly corrosive
effect.

I used the factory through the floor pee-tube system in my DG-101 for
one season, the belly developed a nice stain all the way back to the
tail, and the next annual found corrosion on both the CG hook and the
rudder bellcranks. I switched over to a leg bag the next season.

The suggested solutions here, however, are using much longer rigid
tubes, in an effort dump the fluid farther out in the air stream. This
may well work...

I just carry a couple of medical leg bags behind my
right elbow and dump them when I get back on the ground
The are very tough, well-sealed vinyl - no muss, no
fuss.

For me, the problem with bags is that I have experienced a fairly
significant rate of failure. If things aren't going my way, the bag
will simply refuse to admit fluid, typically with amusing results...

Marc