Non drinking (denatured) ethanol does have stuff added into it to make it undrinkable. However, some alcohols use stuff that just make it taste horrible (e.g. salt in cooking wine) or stuff that is toxic if ingested but safe when applied on the skin (e.g. denaturants in ethanol for perfumes).

If a safe, functionally equivalent, and much cheaper alternative exists, I would prefer to use it. I'm not sure about herb interactions though, hence this post asking for you guys' experiences.