I would do a shoot for only the cost of film and development and that I was hoping to use the photos to build my portfolio

I asked if it would be okay to use them in my portfolio

this is not what the implied deal was

Not being crystal clear about the deal is where you went wrong. You should have said something along the lines of: “I’d be happy to do the shoot for the cost of the film, but strictly on the condition that I have the right to use the photos in my portfolio” (and putting it in writing of course).

That way, either they back out or you’re covered for using the photos for your portfolio.

According to the website: “It contains Propane, Butane, and medicinal grade mineral oil.”

I’m guessing it’s the mineral oil that creates the haze, and the propane and butane are to pressurise and aerosolise it.

You could try your local hardware store if they have mineral oil and some kind of spraying gizmo.