The video was only to demonstrate the oil catching bottle, not noise reduction. If I wanted to reduce engine exhaust pulse noise completely I would do something like this:

Attach a header pipe, not a muffler, to the engine. To the header pipe, attach a silicone tuned pipe connector. From the connector, attach an expanded cone that terminates in a round pipe that is 2" in diameter. Using 2" diameter ducting hose, attach that to a small car muffler that has a 2" diameter inlet and outlet stub.