How to soften VERY hard leather...?

Old saddle bags that I've had for 21 yrs. They are super stiff and hard but I have faith in them. I've saddle soap and dried one flap and then on same flap I've worked in some Pecards leather dressing and used a hair dryer on it while doing it to work it in. It's gotten better but still long way to go...on just one flap. I've heard that you can soak them in water to get them to soften up and then soap clean them, dry then use the Pecards dressing. I really need help here. My Pa gave these to me and now he is passed and I plan on riding again at the end of the month.