[Beav]

I think Raggot, the gerbil, is too big for this job.

Pulling the headliner is the right way to do the job, but sneaking/snaking a semi-rigid tube to each corner and using compressed air will work - IF you can see the drain openings. The downside to that method is too much air can blow the drain hose(s) off of the nipples and cause a nasty stain on your headliner the next time it rains.

Removing the headliner really isn't that difficult, just remove everything - visors, mirror, grab handles, etc. and pop the trim loose. Fold the front seats forward and slide it out through the right-hand door.