Garudapurana 1.117.5

1.117.5

caitre yajetsu rūpāya karpūraṃ prāśayenniśi /
dantadhāvanāṭajaṃ naivedyaṃ śaṣkulīṃ dadet //

In Caitra, one should worship the Well-Formed One, taste camphor at night, / chew a tooth-cleaner made of aṭa, and offer a cake as a food-offering;