What paste goes on the left head of the mridangam?

Before playing, a mridangam player presses a temporary paste onto the centre of the left, bass head. Most sources name semolina (rava) or farina mixed with water; one acoustics paper names a wheat paste. The paste lowers the pitch and damps the head, and players top it up during a performance. Some use silicone caulk, modelling clay or rubber gum instead.