Which is the best way to de-grit clams and mussels? Salt, cornmeal, or salt + cornmeal? What's the most effective way to de-grit clams and mussels? Apparently there are 3 possibilities.

Salt only.

Cornmeal only.

Salt and cornmeal.


Has any academic peer reviewed or researched this? This blog tested just with or without cornmeal:

After 24 hours and 4 water changes, I steamed them in separate pots. The first batch (sans cornmeal purge) had significantly more sand in their bellies and shells and the pot in which they were cooked than the second (with cornmeal purge) batch, but they still tasted of the sea.  The clams in the second batch were lighter in color, plumper, and notably sweeter than the sea.
I think salty water is a given in purging, and the article you shared is no exception to this. Quoting directly

You need lots of water—about 1 gallon of water and 1/3 cup of kosher salt per 1 dozen clams—that should be changed several times over 48 hours in order for them to be squeaky clean

I think salt and cornmeal can be used complementarily. As it’s mentioned in the article cornmeal will alter the taste, but it will also expedite the purging (from 48h to 24h per the experiment in the article).
It looks like using both is a better option than just using salt. And assuming salt should always be present in the water, I would rule out the only cornmeal option.