I mean it cleans using extra fuel, either through cylinder injection or a dedicated injector into the exhaust like the Duramax engines. And it's going to do that every 150-600 miles depending on the vehicle.
Fine print states requires API latest ot ilsac latest. 23 manuals actually state SP. One thing to note is whether or falls into severe service category which would be every 6 months or 4k miles basically. Otherwise it's 1 yr, 8k.
The injectors themselves get crystal build up and they are in constant use. Anything with a layer of def once exposed dries in to a white powder/crystal layer. Reabsorption depends on the how much it's built up.
Had that on both recent bottles of Pennzoil Platinum Euro 0w40 purchased through Walmart less than a year ago. No telling how long they sit in warehouses though.
Oil full of fuel doesn't sound like it would be better. The engines barely run dump fuel each time trying warm up. Old hybrids ran the engine 95% of the time.