Sure, you can use it. The thing to do first is to work some Brooks Proofhide into the underside surface of the saddle (use a toothbrush to get some in the tight spots between leather and saddle frame). Let the saddle absorb that and do it again -- and then do it again after riding the saddle a bit. If you let the leather absorb as much Proofhide as it will, there's every chance that you'll get a lot of use out of the saddle. (Snoseal -- a beeswax-based waterproofer -- will do as a Proofhide substitute. Petroleum-based compounds are to be avoided.)