Doh! Check your facts, Koolcat. Lest our friend Boris here be misled.
Powderized wood vinegar or pyroligneous acid are loose when fresh. Exposure to humidty and moisture will turn them "chunky" first, then totally harden. The "chunkiness" has nothing to do with Dextrin content but is caused by moisture content.
"Chunky" means that the pads are losing their potency because of exposure to moisture. Hard pad is useless.
Don't take my word for it. Try this experiment. Take out a pad from its plastic wrapper and place it in a place where humidty and temperature is high a(i.e. basement.) A week later, check it out as the powder becomes "chunky" because of the caking effect moisture has on the absorbent powder. After a few more weeks, the powder will harden into a brittle flake and become totally useless.