Absolutely agree! I'm very curious about evening primrose...I've ordered some.
As far as rotation goes, I've rotated twice..Sunflower for the first 3 mos. or so, then olive for a couple of weeks, now I'm using flax cuz I've got some that needs to be used up. With each change of oil(2) it was as though I was starting the therapy all over again...the WOW factor.
So I'm convinced that regular oil changes are necessary. For me, more often than every 3 mos... :)