Priming Berkey water filters

Baglady_2

Does anyone have experience with priming the big black filters for the Berkey please? I attempted priming them as per instructions at the kitchen tap, but the "beading" referred to only appeared slightly down one side, though I gave it a good go. So I resorted to plan B, as if we had no mains pressure, and soaking them overnight, again as per instructions. They were still bobbing around and not sunk as they should have been, come the morning. DH suggested we screw them in and just start using, and this would hopefully soak out the air pockets, but this hasn't worked either. They say to unscrew and re-prime, but how likely is that to work if it didn't work first time? Any tips gratefully received, thank you.