What did you drive through? I thought mine was the dirtiest one I ever seen till yours come along. I dont know if you can clean it without removing it. Most of the time you need to remove the rad and blast water from the engine side through the condensor towards the front of the car, if you shoot the water the other way you will blow that stuff deeper into the fins. I bet your car is running warmer.
Let me give you a little advice since I work on radiators and see this alot. Those push pins you installed your tranny cooler with, GET RID of them. Make you some brackets to hold the cooler.
Those push pins wear holes in rad tubes or condensor tubes over time, I've seen a lot of it and got alot of work just because of those things.