Stop in for a cup of coffee

Hmmmm... I like the idea of that but concerned that it'll dislodge something and gum up the whole works.

Automatic transmissions are like black magic for me. I better understand Radio Frequency propagation.
Is yours the bottom coils of an old radiator? I know the trans shop did mine on a flush machine. Backflush first, but I think they run both ways a couple times. Much better than anything I could do DIY. The lines I just blast air through before installing. I rebuilt my trans, and new torque converter so nothing to flush there.