These are the six (sat) ways in which sesame seeds (tila) are utilized for spiritual purification on this Ekadashi. Therefore it is called Sat-tila Ekadashi:

(1) bathe in the water mixed with sesame seeds,
(2) rub sesame seed paste on his body,
(3) offer sesame seeds into the fire in sacrifice,
(4) eat sesame seeds,
(5) give sesame seeds away in charity,
(6) accept charitable gifts of sesame seeds.

– from the narration of the glories of Magh-Krishna Ekadashi, or Sat-tila Ekadashi, from the sacred Bhavishya-Uttara Purana of Srila Krishna Dwaipayana Vyasa.