Real world life expectancy of a high end cartridge?

Mijo, Besides your insistence and your claim that the Last products "smell" like Freon, you have presented no evidence for your claim beyond your observation that it evaporates without leaving a residue.  I guess we're going in circles, but many solvents evaporate, leaving no obvious residue. I think there is a very old thread where someone claimed Stylast was an alcohol, which is why it might harm the adhesive used to bond the stylus to the cantilever, in that person's way of thinking.

By the way, I think brake cleaner, as sold in spray cans, is ether or closely related chemical, not freon.  Ether also does evaporate leaving no detectable residue.  I don't doubt that Stylast is a re-packaging of something not too exotic, and that it is very expensive on a per ounce basis.  But we have lots of testimony, including my own, that one small bottle lasts for years if not decades.  There are much bigger rip-offs in audio.  Of course, I stopped using it a few years ago because of those rumors about damage to the glue or the migrating-up-the-cantilever story. Plus the fact that Magic Eraser works so incredibly well while avoiding any danger that might be posed by any liquid cleaner.
It might be a volatile substance diluted in water, suggesting that after a certain amount of time, the volatile active ingredient may evaporate, leaving only water.

It can be kept in the liquid phase when under high pressure, but I agree with your basic point as regards Stylast.

Moreover to benjie’s comment, how does the suggested experiment “prove” that stylast is Freon? There are any number of liquids that evaporate without leaving a residue.

 I haven’t used stylast for several years. I was skeptical of the idea to use magic eraser. Then I used a microscope to look at Styli before and after a careful magic eraser treatment. That experiment converted me to magic eraser for cleaning my stylus. No liquids. It’s quite remarkable.
I have no beef with stylast. I certainly never had a problem with it. But where there is smoke, there is sometimes fire.  So I prefer not to take a chance.

Elizabeth, Have you ever done a side by side comparison?  One with Stylast and one without?  Of course, you'd have to own two identical cartridges.