My mum had Exelon patches for her LBD.
She found they helped lift what she described as "the fog". It didn't make everything better; she still had executive function problems and fluctuation of abilities. But she felt positive about the improvement she perceived.
She also at times had incredible moments of lucidity and clarity about what was happening - not always a good thing, I felt, as she understood too much; but that was not necessarily to do with the Exelon.
Make the most of the golden moments of clarity with your father