I believe you would have some decent results with trying this out. I do recall reading a method of Japanese growers soaking the logs, then striking them with a mallet to induce fruiting. Apparently the concussion initiates the fruiting sequence.
50-60 F is the temp range for primordia formation and RH should be 95-100%. Stamets says once fruitbodies begin developing, RH should be constantly fluctuated then lowered to 60%RH about 6-12 hours before the fruits are harvested. This is to toughen the skin on the outside, substantially extending shelf life.
Lighting for fruiting is 12/12 as frankenstoen said, although it can be differed from that. If the logs are outside, daylight should be
enough.
I dont have much
experience with Shiitake but plenty with other varieties and I would recommend any of
Paul Stamets books. He is considered one of the greatest mycological minds in the field today. You wont be disappointed, the money is well spent. I got the whole set of books from
www.fungiperfecti.com Check it out