[Mark Yacavone]

Yes , when racers tell you you should have the converter cut open and cleaned and inspected , they are certainly correct.
However, you can take a chance,by not doing so, in your situation.
Most of the long term fine debris in a converter, ends up around the overlap, where the weld seam is, due to centrifugal force . That's probably not going anywhere.
It there's anything recent in there, it's possible to flush it up.

First thing you should do is set it on the bench and place a clear plastic tube all the way in and down to the pilot area. Siphon the remaining ATF out over the edge of the bench.
Then, if you have a parts cleaner, with fresh, clean solvent in it, place the tube all the way in and let it run for a while.
If you don't have that available, then pick up a gallon of mineral spirits and pour in as much as you can. Place a T350 input shaft in the unit and spin the turbine back and forth to stir up the fluid. Then quickly dump what you can into a clean pan. Finish by siphoning out the remainder of the solvent.
Then blow it out thoroughly , best you can .
If you haven't found a big chunks by now, you'll probably be okay, assuming the bearings and thrust washers aren't falling apart.

Disclaimer...You heard this from my ghost writer. Not from me.