I have tried using the Ricola liquid center cough drops, first because I am coughing from the Covid infection, and second because they have a potent menthol flavor that wipes that strange taste out of my mouth. It will be interesting to see if the taste is still in my mouth when I wake up tomorrow.
Also, I feel like I am salivating excessively, so I am wondering if that is my salivary glands trying to excrete the medicine out, resulting in the strange taste, which would be in accordance with your theory on the medication.