chain spray works well tho, as it doesn't blast away with pressure washing, my bike last a year using this method and i pressure wash the bike every week, I've tried the waterproof grease before but they only seem to last about 7-8 months and the problem of the dust getting in shouldn't be a problem if the seals are doing there job right.

Never had to replace any if properly kept, not that I am neccessarily hard on them?

And yes, you may well blow water right past the seals when using the pressure wash! I can pretty mush make the window on your car p*** on you too if I try!

If you fill them with lube, there is no space for the water to go to do damage by corrosion, which leaves only normal wear, and good lube of whatever type should prolong that. Exception being s--t bearing to begin with! And yes, there are bad ones out there, cheap ones as well!