Why are you scared of a fuel additive that has been around longer then you, that's nuts.

 

You need to find your leak, get it pressure tested, fixed and bled properly before you toast your engine.

 

Seafoam is great no reason to fear it if your engine is nice and sealed tight. Like I said I had a slow head gasket leak the seafoam cleaned wide open. It was a good thing though because it got me off my but and learn how to fix an engine. I will add my intake manifolds and fuel injectors were very clean and my truck runs like a million bucks. My advice is to hunt down your leak or at least just get it pressure tested. It's worth $40 for the piece of mind.

 

It hasn't leaked since march now, and I think it is a freeze plug in front of the transmission that is leaking. The system pressurizes when hot and depressurizes after overnight when cold. Stays cool at about 195 to 205, Exhaust is normal and shows no signs of coolant. It has yet to lose any more coolant and the plugs seem to be fine. I had a bunch of little leaks when I got it, most are fixed now but we still call it "Oz" cause its green and it leaks little droplets of w/e it feels like. Its a wizard!