The one being asked about here was a mild abrasive "cleaner" with a glaze mixed in.
Nick clearly states in the original post that it's
non-abrasive, which is why I categorized this as a "pre-wax cleaner".
My sense of the slot for this type of product was in the time frame from when clearcoats became common, but before the explosion of machine polishing in the late 00's. That's the time when the traditional "wax", which had cleaners in it for single-stage paint, was too abrasive for clearcoats, and enthusiasts like us were starting to understand that "waxes" almost always had some (now) non-abrasive cleaners in them, and were starting to separate the steps and use a pre-wax cleaner, and then a "pure" wax.
So every line had a pre-wax cleaner, and as these were frequently oily and acted as a glaze, and as sealants became more popular there was a recognition that the oily component might interfere with the bonding of a sealant, so late in this period we got the sealant-compatible products, like this Blackfire product, Sonus Paintwork Cleanser, and of course the ones that were touted as sealant-compatible glazes, like Danase Wet Glaze, Prima Amigo, and Poorboy's Black Hole and White Diamond.
Although some of these are still available, I think the whole class of products has fallen by the wayside as machine polishing has become so common that people are typically doing an abrasive polishing step. I see P21S still makes their Paintwork Cleanser, but for instance if you look at the Pinnacle Souveran instructions at the Autogeek store, it says to use Pinnacle Paint Cleansing Lotion before applying Souveran, even though that product no longer appears in the store.