I've tried the solder drag method before. I ended up with all the pins connected to eachother. I stopped there. Was I supposed to wick away the excess after that?
It depends a lot on the type of flux. I have just about every type you can get; no-clean liquid, rma223 and others. All will leave bridges except this dark brown gunge I've got that burns really easily. It's ability to completely destroy the surface tension of solder is uncanny and not once has it caused a bridge even on 0.4mm pitch parts.
It will even eliminate other bridges if I paste a bit on the bridge and touch it with the iron. I'd like to know what it is, maybe it's plumbers fluxite or something like that.