RTV isn't good for much. I can only think of a few places to use it on an engine: Front and rear of the intake manifold, to take the place of those stupid cork gaskets. Put a tiny amount around the water passages on the intake gasket too. On the corners where the oil pan gasket meets the rear/front rubber seals. On the bolts that go into water on the front of the engine. On the ends of the rear main seal.... can't think of anywhere else to use it.
That’s what it’s designed for. If one reads the package, it clearly says not to use on gaskets that may be in high contact with oil or gasoline, specifically headgaskets, oil gaskets etc. makes sense why it leaks when used in those locations
