Washed the pants twice. The first time, they came out looking exactly like they did when I put them in. Filthy. The second time, I took Martha's advice (and half a stick of Oxiclean Max) and washed them with a bunch of towels. That apparently weighs them down so they can get good and soaked. The sewn in pads make them float otherwise. Here is the before and after.
Not gonna lie...they could probably stand to go through the wash a third time, but I will use the same philosophy I do with baseball pants. Why try to get them white, when they are just going to go out and get them dirty again. They are clean. It is enough!