Mine now on the 3rd yr. are just the opposite, they are slick. I use Mothers - BACK to BLACK rubber and plastic trim cleaner and it makes them feel new. Also have used plain ole Windex, it cleans the grips pretty good also.
only in really humid weather do they get sticky..which we haven't had much so far this year.
Had the same problem with ISO grips, cleaned tried everything from alchohol to 409. Finally dusted them with a little bit of powder (baby, talc cornstarch) and sticky is gone.
No problem with the PM Renthal grips. My problem is the opposite. The black dye comes off the cheap sh#t leather fingerless gloves I wear in the summer.