Dragonfly, please don't misunderstand me. I was simply replying to Freguson's question. I agree that a good box in good condition should not need more than a decent unwaxed chalk. But, as in the case of the heirloom call I mentioned above, when chalk does not work, rosin just might be what that paddle is looking for. I'm not saying that rosin is a great substitute for chalk. It has a lot of problems and, as you say, it can ruin a paddle. But when chalk does not work, and you want to try to salvage the call, what have you got to lose?
RainChalk does not contain rosin and that is what I try when chalk does not work by itself. But if even RainChalk doesn't pull the call back, I might try rosin either by itself or as a base under either chalk or RainChalk before tossing it into the burn bin.
Bill, that's what I was talking about. Apparently the rosin that Mr Neil gave you works well with the rosin in cypress. But be careful what you replace it with. Pine rosin may work well, but rosin from fir or some other source may have other effects. I even believe that there are real differences in the rosin from various subspecies of pines.
In my opinion, rosin has way too many variants to be used indiscriminately on every call. It should be tried when other measures don't work. But to discard it from your bag of tricks is equally wrong.