This is an old thread, but something came up that's worth mentioning because it didn't get much of a response: smoking with tea, rice, and so forth. This is an old Chinese technique, and it works very well. Barbara Tropp's The Modern Art of Chinese Cooking has several recipes that are reliable.
The big trick is that this kind of smoking does NOT function the way hardwood smoking does. Specifically, you do NOT want to cook the food with the smoke, only flavor it lightly. The cooking part is a separate step. A really strong tea-and-spice smoke would indeed probably be unpleasant-tasting; a light smoking, however, just 15 minutes or so, will impart an elegant whiff of flavor.
These smoke mixtures commonly consist of rice, sugar, tea, and spices. You line a big lidded wok, top and bottom, with foil. Put the mix in the bottom, and put in an oiled rack. Crank the heat until it starts putting up a fair bit of smoke, put the food on the rack, and put the lid on, then crimp the foil. After perhaps a minute, the inside of the wok is dense with smoke. Shut off the heat and wait. After 15 minutes or so, the smoke is pretty much done, and you take the whole shebang outside and open it up. If the flavor isn't strong enough, just repeat the process. When you think it's done, you remove the meat and take it inside, then you wrap up all the foil and throw it away in one go, or it'll stink up the kitchen.
Again, Tropp has good explanations of how to do this. Tea-smoked duck, for example, is lovely.
