Basically Methylated spirits is ethanol with additives including dye. Methylated spirits dissolve essential oils, castor oil, shellac, ball point ink, iodine, grass stains and some medicines. It is also useful for cleaning mirrors and glass as well as paint brushes. It is highly flammable, it should not be used near a naked flame.
Methylated spirits contains methyl alcohol, which is toxic and can cause blindness if drunk.
Always use it in a well-ventilated room and never pour it down the drain. Alternative Use vinegar to clean glass, glycerin to remove grass stains. Whenever I am trying to find out how to do something. I always start by Asking Jeeves.