Seafoam questions...

So. I own a 2006 Mazda RX8.. It has 118000 mileage on original engine. Just today i took it into my local Mazda dealer for a compression test.. Dealer said normal new engines run at 9-10 compression. Mines running at 6.5. And Ive noticed the lose of power:uhh:.. So I was reading around and the dealer suggested this.. The seafoam technique. Unplug the required stuff. ect,ect,ect.. Pump sea foam into vacuum ports Ive watched the videos of people doing it and I get the concept. But my main concern is.. How is this going to effect my engine? Is it bullshit? Does it actually work in clearing the carbon buildup? or will it just wreck my engine and **** my compression more in the long run? Need some quick answers because I was debating on doing it tomorrow morn.. Need some help! Thanks! I don't want to hear people saying "waste of money" either.. Because frankly. It was $15 dollars.. Not a big deal. But if i use it on my engine and it ***** up the seals and ****. That's $7000 dollars for a new engine and installation... Not trying to go through that..

Seafoam questions...