Him: Ella, where does one buy saddle soap?
Me: From a saddlers, generally. But why on earth do you want saddle soap?
Him: To clean my boots.
Me: I'll ask Pa to send you some. There are mountains of it in the tack room.
If you ride regularly, you'll have to clean your tack regularly. Cleaning tack isn't important just to remove the sweat, dirt, and mud it accumulates; it conditions it, too. Tack is exposed to the elements. Tack is made of leather. Leather can dry out, crack, and fracture if not treated well. Nevermind that a full set of tack costs hundreds of pounds, but a broken rein at 30 miles per hour or a lost iron jumping a five-foot fence is frightening. Maybe fatal. So you look after your tack.
Saddle soap — or the sort I grew up using — resembles nothing more than extra-large cakes of translucent golden-coloured glycerine soap. Really, it isn't very much different from glycerine soap: it's a mild detergent mixed with glycerine, or neat's-foot oil, or coconut oil, or beeswax, or some combination of those, and possibly some anti-bacterial and fungicidal additives, too. Now, all manner of liquid and spray-on saddle soaps are available, but the solid variety is what's found in our tack room.
It's not hard to use. You apply it using a damp sponge and work it into a lather. (But don't use it on the seat of the saddle, it makes it slippery.) Then you wipe it off (important to protect the leather from soap damage), and buff the leather to a shine with a clean, dry cloth. Taa-daa: clean, shiny, conditioned tack.
It's good for cleaning boots, too. Or so I've been told.