Memory palace works just fine without CLEAR visualization. CLEAR visualization is when you can do what was claimed of Tesla - move around complex systems and actually see them to scale / detail. There is no way in hell most people can take a transmission and put it together in their head and re-arrange it. Working memory doesn't allow for that, unless it's some entirely different system of processing in the brain.
But if the details are unconstrained conceptually, or not tied to a remembered object, then details won’t be consistent as I move around.
The memory palace thing works for me too, if I am not constantly moving things around.