[sodaclean]

Melt the solder and thwack the board on something hard? So the board stops but the molten solder doesn't.

Sometimes though you just have to pile on solder and flux because the via is small enough that surface tension and heat dissipation means its never coming out

[stavros]

Doesn't a pump make quick work of this?

[sodaclean]

Frequently not. It's always handy to know about extra techniques in soldering.

You can also scale this up in a solder oven and remove almost every single component. Used this for reversing a PCB a few times.