No, not via, or by means of, the rabbi. Sell or gift directly to the rabbi.
Plenty of the people waiting in line think that’s what happens, anyway.
The sale to the goy is invalid, so we seriously ought to sell to the rabbi himself. If he thinks it works, he can then sell his own Chametz and the Chametz he bought from you to the goy and then back.
It’s only fair. Just as with the rest of the legal fictions Jews employ so Jews don’t have to observe Judaism, it’s the rabbis’ fault. Why does anyone suppress the fact the sale is a ridiculous and invalid perversion because the goy has no intention of buying the Chametz at all − not with a downpayment he could not and would not possibly complete? The rabbis created the sale in the first place, and they are its staunchest supporters, now that increasing numbers would prefer to keep the mitzvos of Hashem.
So, sure, go ahead to the sham Mechira. Just make sure it’s clear to everyone present: You’re offloading to the rabbi himself.
There is still the prohibition of Chametz She’avar alav hapesach mederabbanan, if you subsequently take it back (what is Chaim’s chaim worth without whiskey for Lechaim?!). But at least you avoid the awesome Chillul Hashem and the prohibition of owning Chametz on the Pesach.