Oil and Tuff-Stuff leave a thin, liquid film on the surface of the metal. It's easily rubbed off and eventually, like all liquids, it does dry up. A wax leaves a solid coating on the surface that won't brush off in routine handling and that lasts a lot longer.
You can use any good quality wax. Min Wax furniture wax or a good car wax will work. But these products contain other ingredients intended to benefit either wood or automotive paint. Your blade doesn't need any moisturizer or polymerizer or any of that stuff. It just needs to be sealed and protected from the environment. Ren Wax is pure. It doesn't contain any extra wood moisturizer or anything like that. What it contains is wax and a petroleum-spirit carrier. The carrier makes the wax soft and spreadable. But, once you spread it out thin, the carrier evaporates and the wax becomes hard.
When we think of wax, we often think of candle wax which is very soft and will melt at least partially in your hand. The wax used in furniture wax, car wax, or Ren Wax is a much harder wax that melts at a much higher temperature. So, the wax layer that's left behind is hard and able to withstand routine handling.
Some waxes have a problem with buildup over time. With Ren Wax, each time you apply a new layer, the carrier dissolves and removes the old wax. There is no potential for buildup.
Some people worry about using wax on a knife that might subsequently be used for food. Two things are true. First, Ren Wax can be removed with a mild ammonia soluition such as Windex. But, second, you really don't even need to do that. The amount of wax left on the knife is tiny, a layer just a few molecules thick. The wax has no nutritional value, but you probably eat a small amount of wax very often. Many foods, candies especially, have a wax coating on them to give them a nice shine and keep them from drying out internally. A lot of medicine and vitamin pils are wax-coated to make them easier to take and also to increase shelf life. A little wax will do you no harm. (Some people then ask why the Ren Wax label says do not eat. Well, the wax is fine, but the petroleum-spirit carrier chemical is not. But remember that it evaporates when the product is applied and only the wax is left on the blade.)