Flavor is mainly determined by the many terpenes (essential oils) in the plants. In pot there is in the ballpark of 100 different essential oils and they are primarily determined by genetics. It is these essential oils that make up the taste and aroma of marijuana. Period.
There is not a shred of proof to support the assertion that additives can add any flavor to your plants. Lots of marketing hype but no independent studies done in controlled settings.
One way to destroy flavor is by over fertilizing and not flushing the plants at the end of their life cycle. A lot of the pot in Amsterdam in the late 1990's was like that.
Terpene - Wikipedia, the free encyclopedia