Which head of the pakhawaj gets the dough?

On a pakhawaj, the left, bass head gets the dough. Before each performance the player presses a paste of wheat flour (atta) and water onto its centre, which lowers and deepens the bass, and strips it off afterwards; applying it well is a skill in itself. The treble head carries its own paste instead: boiled rice with manganese dust or iron filings.