Mix a tablespoon of mild detergent and a tablespoon of vinegar in 1/2 litre of lukewarm water (for tea stains you can also add a teaspoon of lemon juice). Drench a cloth in the liquid and dab the stain away.
Sprinkle the stain with salt and allow this to work in for some time. Then remove using lukewarm water or mix a tablespoon of mild detergent and a tablespoon of vinegar in 1/2 litre of lukewarm water. Drench a cloth in the liquid and dab the stain away.
First carefully scrape the liquorice off the surface. Then dab the remainder away using a cloth drenched in water and ammonia. If still necessary, treat with water and a clean cloth.