Trying to achieve LARGE grain chemically.... how?

Thank you Bill. I'll be trying this soon. I'm going to have to go shooting again and probably shoot two rolls of the same scene so I can try variety of development. (I'm going to cut the film in half so I have 4 strips)

I am doing some of my own testing based on Bill's testing.

Shot Tri-X at EI=400. I always shoot at ISO speed unless I have a specific reason not to...
Dektol 1:9 70F 6 min....
Over developed a bit and quite grainy. I LOVE IT....
Seems a bit over developed.
This is actually grainer than Delta 3200.

Now doing the same with 5 min....

Going for the grain

I read written pieces every so often from guys going for grain. I always think the same thing. Tri-X in D-76, 35mm. Grainy, but not destructive. You want grainy?--use that Rodinal stuff. That'll ruin the picture, for sure. Grainier than that I can't imagine. (actually I can). 35mm Tri-X, if they even make the stuff, and D-76 which they still do, gives perfect grainy prints on 8x10. Doesn't kill the picture with grain, still very sharp, but grainy for those who like it. Otherwise if you like grain, use a 35mm lens on your 35mm camera, use Tri-X, and develop in Rodinal, blow up to 8x10 and you'll marvel at both grains.