Just finished up. My truck is old, so I had to remove the cover over the electricals, air cleaner box, the duct to the throttle body, and the vacuum reservoir to get to the blower motor. Then 3 8mm screws, the power connector and the little rubber duct and I was in.

I got about 3 or 4 cups of stuff. Single winged seeds, leave bits, and who knows.
Then feeling around, at the bottom of the evaporator, there was a clump of decaying material. I used a popsicle stick and a shop vac and finally blew some air into the condensate drain. I kept probing, then feeling for loose stuff, then probe some more. I also loosened the fender bolts at the top, and the one seen from the door jamb, and pulled the fender away, propped by a piece of wood, and cleaned out the air intake plenum drain.
Mine has a rubber 'flapper' held in place by two christmas tree plastic nails. {if you were to set them on their head, the plastic 'leaves' make it appear to be a very miniature christmas tree} I was able to feel a PILE of stuff in there, and assume it got into the blower because the level was high enough to get sucked over the lip, about 3/4" high, that keeps water out but lets air in. After probing by hand [one finger actually] and then a screwdriver, I dragged out about a cup of stuff, then finally used the shop vac, cupping my hands around the intake hose to concentrate the suction on the plenum. After that, I couldn't feel any loose stuff within finger range.
Put back together... We shall see. The last time I used the A/C, the fan whined like it was rubbing on something, or all the blades were full.
At least nothing had taken root yet.
tom