Learn English – The opposite of “crash” for a stock

Eldritch. It's an adjective, and you can slap it on any geographical feature you want: "an eldritch waste", "an eldritch wild", "an eldritch moor", "an eldritch fen", "an eldritch barrow", etc.

Product is certainly preferable to item being sold, but have to be a little careful how we use it. This seems like a good working definition of the word:

product a set of identical items produced for sale, e.g. "the new product will double our profits"

products multiple of such sets, e.g. "the two new products will quadruple our profits"

You seem to be asking, how do you refer to a single element of such a set?

We observe product is a mass noun which refers to a set of things. Bars of soap and liters of water use units to identify a discrete part of the mass nouns soap and water. Similarly, unit of product could be used to identify a single item to be sold, although it sounds overly formal and almost academic.

"Check that all the units of product are properly packaged."

"Each unit of product must be tested before going on the shelf."

"Count how many deluxe units of product are in stock."

Another option is to use notional agreement, a grammatical convention that allows a group noun to be used with a plural verb when the individuality of its parts is important. This type of construct sounds strange to me, but it is purportedly not as rare in British English.

"Check that all the product are properly packaged."

"Count how many deluxe product are in stock."

Going by ear, the second example ("Each of the product must be tested") is almost certainly wrong, although a real plural noun would work ("Each of the widgets must be tested"). Either notionally plural nouns are more limited than syntactically plural nouns, or my American ears are balking at something technically acceptable.

Although I hope we all enjoyed this brief look into mass nouns, I suggest you use item or unit in those sentences, or, if applicable, identify the thing being packaged, shelved, or stocked more specifically.