At one time I had a batch of plants that just wouldn't seem to ever really dry out, which really bugged me. I figured, among other things, it meant the plants weren't using the water very efficiently, if at all (lock-out?)
This was during early flowering, under 600W hps, so the heat alone should've taken some water, and I'm guessing it was, just not much (wet roots)
I ended up using a bar-b-que skewer(s) to aerate, loosen, tenderize, etc . . . the soil, by sticking it down thru the soil multiple times all around the planter. Don't force it through any thicker roots you might encounter.
Allowed my 2 gallon pots to dry in 4 daze instead of 2 weeks, which has to be better for the overall health of the plant.