I think I've found a trick that makes the burg more manageable. If I hang around near the bonfire, I get invaded constantly, both DW and DMB. But if I move right to the beginning of the level, on that little platform with the two guys, below the crossbow railing area, or better still jump up onto the parapet where the corpse with the humanity is, I almost never get invaded. This is before where the first fog gate originally was in the level, so my pet theory is that somehow invasions aren't permitted unless you go beyond where that fog gate was (it was in the doorway next to that firebomb throwing hollow). But people can still drop signs there, so you can go there and summon friends more easily, then head up to the main arena area.
Also, random aside, here's another fun and recent FH video. Apologies if it has been posted before, but I didn't recall seeing it. Among other highlights, he lands a double parry at around 1:50.