Human urine contains very high levels of sodium.
Cannabis plants cannot tolerate more than TRACE levels of sodium.
Do what you want; they're YOUR plants.

Only application of pee I've found is scent-marking outdoor crops with predator urine (any carnivore; human is fine if you eat meat rrrrar!) to scare off bambi and bugs, who are both looking for a nice pot salad.

Edit: Rusty's right; the compost heap is the only place for pissin'.