Can Blue Vervain Tea Help to Expel Mucus?

I've been told that blue vervain tea can help to get rid of phlegm & mucus in the body areas like throat and thyroid.

Blue vervain (Verbena hastata) is commonly used in herbal medicine, in the form of tea or tincture, as a digestive and calming remedy. It also has expectorant properties, so can be used to liquefy and expel mucus from the bronchials. I have not used it for this purpose, so have no experience of its effectiveness.