dave.
he is mixing it with the upholstery prespray because it has ammonia in it which act as an accelerator, you might as well just use ammonia.
I would not use a steamer like he is using as it has a surface area of about 3 inches x 8 inches I would use an iron were you can use the tip as a more precise way of applying heat.
the funny thing about this video is he is making the most basic mistake in stain removal, near the end he says
"there is transfer of the stain onto the towel were we have not applied the product"
why is he using a bleaching stain removal technique when a less aggressive procedure will remove the stain, of course he is just making a video to show a product but they sould have eddited out that comment