Part of the resistance to more widespread use may be just with the concept. This is a fire protection system, and for some fire departments the notion that they're there to put out the fires may be more deeply ingrown than is obvious.

The fire department doesn't install sprinkler systems either.

Maybe your local "security systems" people could sell a contract to appear at just the right time to slather up your house, as a rider on your intrusion alarm systems and neighborhood patrols?

The linked article mentions equipment price:

Sabo has developed a $12,000¹-to-$20,000 gel system that can be attached to fire trucks and recently has begun to sell it to fire departments. (By comparison, a compressed-air foam system for a fire truck, which is what most fire departments use to protect homes, costs about $80,000.) The gel is made by such companies as Barricade International of Hobe Sound, Fla.

¹ I paid about half that for my first (home office) laser printer, about 15 years ago. [It had a few accessories.]

A vague reference to "a few hundred dollars" to protect a home seems to be the only reference to the cost of the gel(?) - in this article.

John