I was looking at some deer-tongue earlier today to be bought bulk. I was curious as a former herbologist why it was used. Reduce inflammation, irritation and swelling, induces perspiration. Apparently it has been used to treat snakebite and gonorrhea (probably symptomatically). Main non-herbal use is to rehabilitate poor soils and to flavor tobacco. Medically they caution its use because its main ingredient is coumarin which thins the blood and may lead to liver damage, but then, half the pills out there shoved at you do that too.
Somewhat related or similar to Tonka beans, it is sweet tasting and very aromatic, but can cause a number of allergic reactions along with certain other flowers (like chrysanthemums). Probably the stuff they use in a lot of these Lakeland blends and if you have allergic tendencies toward that family of plants, probably why a lot of people are repelled by the stuff!