The problem with anything alcoholic or astringent is that it ultimately dries the throat and can cause damage. Lubrication is the goal, so anything with glycerine or other slimey stuff- slipper elm, mallow, honey... and warm but not hot liquid.
Even as a shanty singer, remember to be judicious with the key so it's in your best range. Support your voice with good cushion of air and let it "fly" out of your forehead rather than pushing from your throat. Some people use images like a fountain, or an eagle riding a thermal. You can sing all night with proper technique

good luck- Julia