Yeah, the W3X has the waxed outer shell that makes it more water resistant than the other jackets. It also unfortunately makes it dryclean only if you want to keep it water resistant.
If you don't care about water resistance, then you can just wash it normally and the wax will slowly come off, leaving the coat with a dull finish. It will still be warm as heck.
Keep in mind that the N3B "snorkel" parka (so-called because you can zip the hood up, leaving a small hole for your eyes) was a military spec contract for decades so a number of manufacturers have versions of it. Alpha Industries is just one of them.