I heard similar ideas.. My first teacher insisted that I practiced difficult passages staccato, to make it more difficult than it is. In that way, it would feel easier when I played it normally.
It worked well for me. But now, when I changed teacher (and therefore obviously changed approach) I don't do it anymore. Now I have a more "Musical" (in lack of better words) way of practicing. I play it the way I want it to sound, all the way from the first read.
I know that there were pianists from the golden age who would agree with both of them. Busoni had ideas about picking the most difficult fingering, to later feel at ease when choosing the easy one. At the same time, there were other pianists who said "Play it as it should be played, but in a slower tempo. If something is written legato, practice it legato".
So if it works, it works...