How to create an invisble category (for sold items)

Hello, i am in process of setting up opencart 3 store. I am selling "unique" 1 off items, meaning once sold, i will be disabling the product from store view, or what i would like to do, and the reason for the question is this...

Can I create a "Sold" Category, Hide it from top menu, and also hide it from the side view menu also. (only accessible via a direct link hidden from world, i am undecided at moment if i want to show category, but want to have option to add "Sold Items" later on)

I want the product pages of sold products to be "accessible" should someone have it bookmarked and goes back to it (i dont want them to get a not found error), but i dont want the products that are "out of stock" (sold) to show anywhere in the store. My Add to cart button currently greys out when an item is out of stock. I am using journal 2 theme in addition.

Simply unlink the product from any category.

They will still be accessible from old product links and searchable in the store search.