How about using essential oils for flavoring? They are extracted from a natural source, have healing benefits such as peppermint and smell great??? anyone ever tried this??
In my limited experience (although I have to advantage of learning from my friends who have been growing for years) I have found it best not to add anything other than a balanced fertiliser and water to your ganja. That's assuming you want to flavor it before you harvest. Most of the time adding funny stuff (especially OILs) to youre soil doesn't help with anything. I have experimented with the following: When I harvested one plant, I washed it's roots off with a hose and stuck it in a bucket of diluted mango juice in water for about three hours. I even recommend leaving the plant in the open air (dry roots) for ten minutes or so to get it desperate for water before putting it in the bucket. PROBELM: The taste. Although the smell from the dried buds was very nice (VERY MANGO LIKE) the taste was like burning sugar - and I suspect that is just what it was. You could try to flavor you gear after harvest during curing. If you put some orange peel in your glass jar with the gear (make sure it(the ganja) is almost dry first or it won't leach the moisture out of the peel). You will then get a really nice smell to it, but the taste will be the same. Ultimately, try to get strains that are naturally 'fruity'. There are plenty about, perhaps some of the more learned growers here could suggest some particular strains. Good luck.