Renew-it is not a cleaner, per se; it is a polish with Hook-it in it, as the cleaning agent. You should't use it on dull balls because it will polish them. It will clean balls, but I'd only suggest it for cleaning highly polished balls, if you also want to add some polish to them. Otherwise, it's a waste of money to use it just as a cleaner.
Liquid Nitro is their cleaner approved for use DURING bowling. It is among the best, in my tests, of those approved for use during bowling by the USBC.
Hook-it is one of the strongest bowling ball cleaners made, for use BEFORE & AFTER bowling. It is right up there with Clean and Dull (which does not dull balls). Both actual can draw some oil out of the top layer of the ball. Both are so strong, I would suggest only using them once every 3 - 4 outing with a ball., unless you bowl on oil soaked, heavy oil patterns, which eliminates about 99.99% of all house patterns.