I recently switched to marine trailer wheel bearing grease (ie supposed to survive immersion on the boat ramp) because I was having somewhat irrational difficulty accepting that something as "clean" as a squeeze tube of white lithium grease could really do the job... though in reality it's probably just as good.
At least the blue/green marine stuff is satisfyingly messy to pack bearings with, and they run better than with the dried out goop I usually find in there.
(And yes, I have generally headed the idea that one should flush and clean all the old grease out before repacking with something different)