Floor Friction - Shoe Soles
Dance shoe soles are chrome tanned split leather; street shoe soles are vegetable tanned grain leather. Based on perceptions, but not careful measurements, I believe that the primary advantage of chrome tanned cowhide soles over vegetable tanned cowhide soles is that the chrome tanned soles have sliding friction more nearly the same as static friction. Vegetable tanned leather is dense, hard and stiff. It is mainly used for street shoe soles. Chrome tanned leather is light, soft and flexible. It is used for shoe uppers, gloves, handbags, jackets and upholstery. Most leather is chrome tanned. Since leather is too thick for most uses, it is split to make it thinner. The smooth outer layer is known as grain leather. The rough inner layer is known as split leather. The split leather is not of much use and is actually discarded by some leather manufacturers. Dance shoes use chrome tanned split leather. Chrome tanned leather is usually treated with any of several different fillers to affect its flexibility and other properties, which also incidentally affect its frictional properties. I do not yet know how the best dance shoe leather is treated. On bare hardwood well worn leather of both chrome tanned and vegetable tanned soles are similar in friction. On other finishes there can be big differences in the friction of the two kinds of leather. On some finishes one will be slicker, on other finishes the other will be slicker.
Brand new dance shoes are sticky. I do not know how long it takes to break in a new pair of shoes, but 30 hours of dancing is probably enough. New shoes should never be used to test the suitability of a floor for dancing. Fortunately, the right friction is not so critical for absolute beginners. By the time they have learned their steps, their new shoes will be broken in enough to have nearly the right friction. When dance shoe soles are new, they are rough, soft and dull, and look like suede. After they are used a while, they become hard, slick and shiny. A coarse, stiff wire brush could presumably fluff up the leather and make a used sole stickier like a new one. I would be afraid that this would wear out the leather prematurely. For removing wax buildup without fluffing up the leather I prefer a small fine steel wire brush like is sold at auto parts stores for cleaning engine parts.
The only floor you have available for practice dancing may have far from ideal friction against chrome tanned leather. If you cannot change the floor wax, then change the type of shoe soles until you get as close as you can to the proper friction. From the slickest to the least slick, soles that I have used are Teflon, Dexter soles, cowhide, and rubber. When I will be dancing on a new floor, I wear dress shoes with Neoprene rubber soles, and carry two pairs of shoes in my shoe bag, one with chrome tanned split cowhide soles, and one with Dexter soles. This assortment of rubber, cowhide and Dexter soles will work for almost any floor. Teflon and Dexter soles can be obtained at the bowling supplies counter at bowling alleys. True-Slide modified Teflon patches work for the very stickiest floors. They are made by Master Industries, Irvine CA. Dexter soles are supplied by Dexter Shoe Co., Dexter ME with Velcro on one side for their bowling shoes with interchangeable soles. Their sole that I refer to here as the Dexter sole is the one they call "longest slide". I have not attempted to use interchangeable soles on my dance shoes. I used a pair of pliers to remove the Velcro, and glued the Dexter sole on an old pair of street shoes. Chrome tanned cowhide soles can be obtained from suppliers of ballroom dance shoes. Their natural color is a bluish grey, but they are often dyed black or tan. However, the replacement soles sold separately are sometimes stickier than the soles on new dance shoes. A dance club might be better off buying chrome tanned split leather directly from a leather supplier. The soles can be glued on old worn out dress shoes or even tennis shoes for practice in a gym.
Men's dress shoes can easily be found with rubber soles. There are several kinds of rubber; I have only tried Neoprene. Ladies who want rubber soles on real dance shoes will have to buy sheet rubber to glue on. Sandpaper an old shoe until it is very clean before gluing a new sole on it, or the glue will not stick. True-Slide soles come packaged with special glue. For the others, use a good grade of contact cement. If you do not want to glue soles on yourself, your local shoe repair shop will do it for you.