Oh its pretty much every one of them. I have started cutting my dunk time down to under 10 minutes for both soap phase and rinse phase combined, and cutting the amount of detergent down to just a drop or two, hoping maybe that will help to not remove too much natural oil from them. I have to get the first CPR coat on within 2 hours or the bag will be dry to the touch already. Then I try to wait about 6 hours until the next coat but usually its overnight if I start the dunk in the afternoon. My Winnie that I just dunked got 3 coats of CPR, a coat of Renapur and a coat of Blackrocks and after two to three days, it still felt a little dry and rough on the outer sides and just did not feel like it did before I started. Yes, maybe your older bags that have been used more have oils from our hands and such deep in the leather so that is what makes the difference.