My wife and I just got finished rescueing an old western saddle that one of my neihbors gave me.
The poor thing had been laying in the dirt for years, had patches of mold, was bent out of shape so bad that it was almost flat and was just covered in dirt. The leather was so dried and stiff that I was afraid to try to bend it for fear that it might crack.
The first thing I did was get my wife's vacume-cleaner after it.
Then I set it over a carpenter's saw-horse, wet it real good and scrubbed it with a mild dish-soap solution.
We then used a water hose to rinse it well, reshaped the now-wet leather, and let it dry for 3 days.
Once dried, I used a bit of diluted mold-remover on the little bit of remaining mold, re-rinsed the entire saddle untill it was soaking-wet again, touched-up the shape and let it dry another 3 days.
At that point it at least LOOKED like a saddle again.
Over the next few days, it got 3 applications of Nesfoot(sp?) oil, about 4 days apart which not only made it pliable again, it put some oil in there so's the up-coming dye wouldn't attack the leather.
A few days AFTER the third oil-treatment, my wife dyed it with some alcohol-based, black leather dye. It took 3 applications of that also, 2 days apart...and then we let it sit for 3 days after the last one.
After buffing all of the now-dyed leather with dry rags, it got a single application of a cream-type saddle conditioner which contained lanolin. I forget the brand we used but it took the whole can which BTW, completely soaked into the leather after 24 hours.
At present, she's ridden with it but is still in the proccess of rubbing boot wax into it.
And just so you'll know.... buffing the saddle after the first boot-wax treatment also lifted-out the little bit of remaining dye which didn't soak in. Had she not done a good job of buffing, I'm certain that it would have stained her jeans instead.
It took 3 applications of wax before it finaly glossed-over a little and the wax showed signs of sealing the leather. That is the point of the rescue in which it was finaly useable again.
She's done the wax/buff routine it a few times since then and today, ya wouldn't know it from one that had been well-kept all of it's life.
I hope that I explained all of this well and I do apologize for the long post. My purpose in all this was to point out that here's worse things can happen to leather than just being dirty.And that almost any saddle can be salvaged.
Maybe you've found something here to be helpfull.