Seafoam, Anyone use it? Options

[blu94gt]

So I've been thinking about running some Seafoam through my engine. A lot of guys in various clubs with me here have done the same and say it's amazing. My friend's Audi TT was having some valve chatter and such and he cleaned it with Seafoam and now it's PERFECT.

For those who don't know, Seafoam is an engine cleaner/carbon deposit remover. Supposed to put 1/3 in your gas tank, 1/3 in your oil, and 1/3 through a vacuum line like the brake booster then run the car for about 15 minutes (it'll smoke and everything a LOT) then change your oil and boom your done.

What I've heard though is on higher mileage engines it's bad to use something like this because the carbon deposits etc that it cleans out could be blocking leaks, and when they're gone you could spring some engine leaks.

Feedback anyone? I need stuff to do this week lol