I actually use the gray sealant from Right Stuff. It is very versatile and dries quick. You can actually put it in use within 10-15min after application. It is OEM approved for most imports. It is higher temp than blue rtv and can reliably replace a gasket if necessary.
The oil pan gasket on rotary engines are notorious for leaking because of the varying expansion rates of the plates. Many of the new engine builders will use only Right Stuff to seal the pan, sans gasket, and never worry about leaks again.
I have been using it for about 5yrs now and everything from front covers to water pumps, and never had one hint of seepage or leaking.
I'm going to use it on my timing cover and rear cover and t-stat gaskets, and have seriously thought of not even using a gasket and only putting the Right Stuff on and seeing how it works. But the rear cover and front cover a PITA to get to and check for seepage or fix if it did leak, so I haven't decided yet.
here is from the Permatex info:
The Right Stuff Grey Gasket Maker was specifically designed to perform under the higher torque loads caused by engines with closely spaced bolt patterns (typically import vehicles, particularly Japanese). It is is blowout resistant, allowing leakproof gaskets to be made and put into service in just one minute. Sensor-safe, this product seals instantly, forming a reliable, long lasting elastomeric rubber gasket that outperforms precut gaskets. OEM specified by Honda, Nissan and Mazda. This product is resistant to powertrain fluids (oil, coolant, and ATF) and operates in environments to 450°F (232°C) continuous; 500°F (260°C) intermittent.