Hey guys, so whenever I come near the end of a bowl and am at my last bits of meth, I tend to use a pipette to drip a few drops of water down the neck of the pipe to get all that white stuff coating it, and cover both holes of the pipe and shake the water a few times so as to get everything dissolved in the water, then I boil the water off with my lighter and start smoking once only the meth remains. I've done this for like almost two years now, but the other day I got some meth from the guy I normally get it from and noticed that this meth does not dissolve as easily as all my other meth did. Like even after I shake vigorously a few times, some hardened meth still remains. I was honestly kind of shocked because I have never experienced this before. I did eventually get all of it to dissolve in the water, but I am a bit worried now. What would be causing this?