It's a penetrating oil, as a bore cleaner it's as good as WD40, if Kroil is working for you no reason not to use it. For stubborn deposits you might want to pick up some J-B bore cleaning paste to go with the Kroil.
Remember it is a penetrating oil and it does penetrate very well, it might be the best. I've used it on some RUSTY nuts and bolts, I thought were never coming apart. A little soak time and they unscrewed.
I have been using Hoppe's Elite Gun Cleaner lately, mainly for the low odor -scent free aspect. It does clean and it smells good.
My wife doesn't even say a word after a cleaning session in the bedroom and I put it on the nightstand. I have used others that even I couldn't stand the stink !

Gary