Pairing up with a Biochemist to multiply some mushrooms is amusing, too. :3
I'm not sure about faster...
get a bio and ws (with dbss) to party..
bio plant mushroom on the same spot using the all available mushroom spores..
after that.. ws hit and greed..
u will see the number of mushroom spore increases...
^^
i dunno if theres a map where u can hunt mushroom spores easily..