I don't know if I am thinking of the same plants or not, but years ago, at our old house, I had a white flowered "fortnight lily" growing in a barrel. (Iirc it had some blue and yellow parts to the flower.) I really liked it, and asked the landscape designer to put a few in here at the present house.
Guess what... we got the uglier (imho) beige and brown flowered ones...
Fortunately they are way out in the "Back 40", so they aren't up and in my face, but still...
I had never heard of cutting them to the ground, though. I still have them, but they are overgrown and mangy looking. Maybe we should give that a try.