These coatings get to sit on wheels, under-bonnet parts, all sorts which get a LOT hotter than your brush will, even with your demon whisking technique!
I'll drop him a line and see what he thinks ...
What the coating will do is put a nano sized layer of sealant onto the surface, microscopically levelling it out and producing a pure flat surface which NOTHING can adhere to. Water does a full lotus effect, whole round bead, soap will not wash it off. To remove it needs to be sanded off. To get the best out of the product, the knot should be removed so you can seal around the very top.
Here's their plastic coating on one of my old cars - the initial surface was washed and then scrubbed with neat IPA first.
... it goes mad shiny and will stay like on automotive surfaces (think: dust, salt, rain, washing, wind) for 12-18 months without issue. On a brush handle in soapy water, I think that would increase exponentially. The actual coating is not especially thick, despite what it looks like ... well, it's nano in thickness, but it does make the surface very slick since it is microscopically perfectly flat. That may be a negative.