There's absolutely no legitimate argument that treating and/or pressing tips makes a difference. People have been doing it ever since leather was first introduced to the front of cues. If it's a bogus hogwash notion, then there has been 300 years of fools, to include most of the biggest names in cue making. The question isn't why anybody would believe a .$40 tip can be soaked in something & become magically better. The question is why wouldn't somebody believe it?
It's nothing to do with magic. It's science. The simplest formula I know of is milk, but even that has more than meets the eye. Milk contains a protein called casein. The amount differs from one species to another, but all milk has it. Horse hide also contains it. It's commonly used in glue and food binders. What does that mean for tips? It reinforces the leather fibers, not unlike what we do with acrylic stabilizing woods. Reinforcement means increased stability, which translates into increased consistency. It's science, not magic. Many of us have stepped out of the casein box and looked into modern binders. I personally use a man-made chemical. Mr. Wayne referenced a builder who used a common woodworking chemical. I know of one guy who uses ammonia. There must be thousands of recipes, with milk likely being the oldest & most known. Point being, it works, and works very well. Like anything else, it takes a learning curve. You're likely not going to get the results you want on first try. Keep at it and you'll figure it out.