May 14, 2018· Grind the ingredients to a powder. You can use your home grinder or take it to a grinding mill. In any case, it is important to ensure that the grinder is not used to grind spices since even the slightest tinge of spice can cause irritation. 3. Store the Nalangu Maavu Herbal Bath Powder in an airtight container in a cool and dry place.