After the chametz is burnt, recite the following "nullification statement,"
renouncing all ownership of any chametz that may still remain in your
possession:
All leaven and anything leavened that is in my
possession, whether I have seen it or not, whether I have observed it or not,
whether I have removed it or not, shall be considered nullified and ownerless
as the dust of the earth.
(The nullification statement recited last night was only for chametz that was
missed in the search, but did not include chametz set aside to be sold or eaten
in the morning. Today's statement covers any and all chametz that may
still be in your possession, and serves as a final "safety measure" for a chametz-less Passover.)
Remember that both the burning and the nullifying of the chametz must be concluded before the deadline for getting rid of chametz, which is one "seasonal hour" before midday.
You are now chametz-free, physically and spiritually -- and free to fully
enjoy the liberating experience of the Seder rituals and the eight-day Festival
of Freedom.