Rahu remedies are kept on Saturday: chant Om Bhram Bhreem Bhraum Sah Rahave Namah, donate blankets, black sesame seeds, and keep the weekday fast. Hessonite Garnet is the graha's stone, but it should only be worn once Rahu has been established as a functional benefic for your lagna.
Rahu remedies are for obsession, addiction and the appetite that cannot be satisfied. Rahu has no day and no temple of its own in classical reckoning, so its remedies are behavioural before they are ritual.
An afflicted Rahu shows as anxiety, addiction, scandal and chasing what recedes as you approach it. Durga and Bhairava worship, and eclipse-day practice, are the classical response.
The mantra, the weekday fast and the charity are safe for anyone — they address Rahu without amplifying it. Hessonite Garnet is not: a planetary gem strengthens whatever the graha is already doing, so it needs a chart reading first.
Saturday. Fasting, charity and mantra japa for Rahu all belong to that day.
The classical Sankhya is 18,000 repetitions, completed over weeks rather than at once. Begin with one mala — 108 — a day and build up; sincerity matters more than arithmetic.
Most charts should not wear Hessonite Garnet at all. It is prescribed only where the node's dispositor is strong, where it sits in an upachaya house, and for a specific purpose named by a qualified astrologer.