Generally there are three guidelines mentioned in the letter regarding care of the Israeli Esrogim after Sukkos:
- Do not cut or ruin the Esrog in any way, including putting cloves into it or letting children play with it.
- Send the Esrog back to Eretz Yisroel, so the Mitzvah of Biur can be done with it.
- If that is not possible, place the Esrog in an open place, in which it will not become quickly ruined, and leave it there until it will become completely dry and not edible. It may then be disposed of.