I wouldn't use anything on my leather except a product designed for tack. It's a lot more expensive to replace a saddle with rotted stitching than it is to buy a good tack conditioner.
I have a system for cleaning leather that I learned on the track years ago. I clean the leather first with glycerine saddle soap. Then I rub a damp sponge on the soap and then dab it in lexol conditioner. I then apply it to the clean saddle. It works great and keeps the leather supple.
"A government big enough to give you everything you want, is big enough to take away everything you have."