Don't know if this would work to prevent boil overs in homebrewing...but the video shows it working pretty well. Only downsize is the biggest opening you can use is 10" so it may not work with a lot of potshttp://www2.pulsetv.com/Boil-Over-Sa...ductinfo/6198/
Looks cool. Too bad they are not bigger
Kevin - One Arm Brewery
"People who drink light beer dont like the taste of beer; they just like to pee a lot."
As with most things "As seen on TV" I'd avoid these gadgets like the plague. Because someone "invented" them and markets them aggressively doesn't mean they're any good.
With the density of the foam of some of my almost boil-overs, I think something like that might just float on the foam.
It's seems to work for water though... At least that's what the guy on tv said.
Ice cubes. Breaks the surface tension. Usually two to four and you're good.
I didn't watch the vid but a spray bottle full of water usually does the trick, spray at the foam and it'll keep it down.