The product I use is Dorland's Wax Medium. I spread it on with a cloth and then buff it until I like the feel and look of it. I have also just used sheets of wax paper to buff pages. It takes longer, but it is a pleasant way to occupy your hands while watching TV.
I bought some clear shoe polish I'm going to try sometime. Seems like it should work fine - but it might smell bad. Sometimes I use hot wax but do not have the knack for getting it on thin enough for just a light coating.
Why wax? The feel of the page. The look of the page. Protects the page. Helps solve sticking problems. It's fun.