The Purdues are identical to the old K4's you could cold shake, I wouldn't advise even attempting to do that anymore though, it's simply not safe period. Even with the rather small amount of binders in the Purdue P4's. I banged one a week ago and even though very little filler was left behind it still left behind some. I always just get the M4's as my normal prescription, run them through a .20um Micron filter and end up with the safest possible way to IV a Dilaudid pill. It aint "safe" but it's as safe as it's going to get. I cotton filter once, .20um micron filter, backload, use everything "clean" and bang.
Like you my average dose always ranges between 8-12mg's with the M4's. With the Purdue P4's I was actually able to get off REAL good with a 4mg. I wouldn't even feel that with an M4, it was pretty crazy how well the Purdue 4mg broke down and worked. I wasn't expecting much and I got hit by a train IV'ing it. The micron filter even managed to get rid of the yellow die.