I've found that overnight in the oven on the rack with only the pilot going can dryout quite a lot a bud without ever getting close enough to temperatures that should degrade the thc. The double boiler thing sounds more like making cannabutter than a method to dry bud, sounds entrigueing, but how would you burn your bud with butter on it? If you think I might be confused, your right. The double boiler idea, I do think is good, when water boils at 212F and THC starts vaporizing at > 225F then you have a safety margin built into your method. Freaze dried is another method you might try. If your aim is to harvest at peak "ripeness" I would look to the tricomes on the buds. Use a jewelers loop 15X to 30X power and look for 'your choice' a. Milky Tricomes =higher-THC = better head buzz, b. Amber Tricomes = higher- cbc/cbn= better body buzz.