Generally the main issues I found were that it degraded over time and I had real trouble with ferrofluid smearing on the container.
Will have to try again now!
https://uk.vwr.com/store/product/2994602/repelcote-vs-water-...
which coats the glass with a layer of silicone polymer.
Not entirely unlike some automotive silicone "waxes" which repel hydrous materials.
Or treatment of the glassware with the much more hazardous dimethyldichlorosilane (DMCS), which actually reacts strongly with the the glass surface at the molecular "sticky points" (which otherwise cause water to wet clean untreated glass and form a H2O film rather than bead up).
The DMCS is pretty rough and you need to handle it under a hood since it can give off more "smoke" consisting of pure HCL vapor sometimes when you open the bottle, compared to opening concentrated hydrochloric acid.
And it eats through the bottle's plastic closure every few years, so it's one of the ones that you need to keep an eye on and replace the cap as needed.
But you get some pretty slick glassware.
But 12 grand!? Wow.