I dunked my 'new-to-me' vintage backpack today and I think it went well. The water was very dirty, so I'm really glad I did it. Now I'm just waiting for it to dry a bit so I can apply the Leather CPR (I also purchased Blackrock Leather 'n Rich). Crossing my fingers it goes well. Thanks again to those who helped!
By the way, once dry will the suede interior cause color transfer on a light-colored wallet, etc.? The interior created more dirty water seepage while I was dunking, so now I'm wondering...