Fistfighters stall when Geralt switches from attack to dodge allowing him to quickly beat them while taking no damage.It also works for meteorite swords and the rune sword in Chapter V.) (Update: new information indicates that all oils which increase critical effect damage may permanently apply their effects on the sword used if a game is saved with the oil applied and then loaded again).
(Tested on Gwalhir in Chapter IV, had no other effects on Geralt or the blade.
Others seem to be able to run it without crashing too often.
Frequent crashes have been reported by some people playing on Windows Vista.Random crashing, often when (auto)saving.