i had a trainer tell me about using ivory dish soap. just a squirt in a bucket of warm water. i haven't bought saddle soap since! it's amazing. you must condition your saddle after though since there isn't any conditioner added to it. Passier's lederbasalm is my favorite. (no idea if i spelled that right!)
yep, the trainer who told me is a grand prix rider who has a tad coffin saddle (which i believe starts off around $5,500). i figured if she used it on that and loved it, i'd try it! it definitely works better then a lot of other saddle soaps out there! and for a fraction of the cost!