I didn't watch the vid because I've done this, it makes incredibly dense black smoke and lots of it when it burns. I'm surprised nobody called the fire department.

It's also not military grade napam but it honestly isn't that difficult to make the real stuff.

Definition of aluminum soap : any of various aluminum salts of higher carboxylic acids (as fatty acids) including aluminum stearate and aluminum resinate that are amorphous solids insoluble in water but soluble in hydrocarbon solvents and that are used chiefly in lubricating greases, in protective coatings, and in waterproofing compositions

That's what you need rather than styrofoam.