You are so right.....don't ever use that crap, it will likely gum up your entire cooling system, not just the radiator!

And be sure you have a coolant leak before you jump the gun.......if the weather's hot and you are using A/C, then it's normal to get water (condensation) on the ground.

Check you coolant level, and check it again to see if it has dropped. If it drops significantly, then you have a leak.