I have always had quite an opposite opinion about compressing high gain guitars. Personally I love it, my current mixes up on the net do not have compression on them only because compressing for dynamic musicality is a new thing that I have just gotten the hand of. I always plug Colin Richardson for his work with trivium and Slipknot as the end all say all result of good compression, Ola in his guitar tutorial plugged in the same idea. Set the threshold so that static strumming is not being compressed, but as soon as any palm muting has taken place, the extra volume ducks the whole signal. With slow attack and fast release, you get this pumping sound that exaggerates tube sag and makes the guitars sound as if they are coming out of the speakers to strangle you and also making it sound as if the amp is giving out in the pure stress of cranking it up. It sounds like everything is being pushed beyond the limit, breaking, and super fucking pissed.
I don't use compression for killing dynamic, I use it to increase dynamic. And to the OP, no you cannot use compression to add crunch to your tone, you need to go back to the drawing board buddy.