Yeah, just if you use it, be smart about it. Don't let it flow through, or dry in areas that don't need it. Meaning, disconnect heater core before using and flush radiator before drying.

The first bottle didn't work. I had even run the engine without #5 spark plug, so there would be no back pressure impeding the incoming liquid. None of that crap worked. I just had to drive with it for 500 miles with no thermostat. Of course, you'll want to do that in the summer when you don't need the heater core. I blocked off a part of the radiator with cardboard so it would overheat slightly and keep coolant pressure high, to push it through. I also disconnected the overflow hose (didn't want the stuff in overflow bottle) and ran the overflow hose into a glass bottle (wont melt), which I stuck down near the manifold. Once a day, I'd pour the overflow back into the radiator, so it would keep filled. Even after the 500 miles, it didn't seem to work completely at first. I was still losing a little coolant, albeit, much less. After about a week, it completely sealed up. Weird stuff.

2003 Dodge Dakota Quad Cab SLT
4.7L V8, Automatic (545RFE), RWD
263K