If you need to clean the solder out of a really solid ground plane hole (someone removed a part with a heat gun and now I need to put a new part in) a way I found that works ok is to use a long run of stranded hookup wire that I've dipped in flux, and a hot air gun. I can heat the plane and push the wire through the hole, soaking up solder along the wire length. It's like penetrating solder wick. It's less stressful than pushing really hard on vias to get good heat transfer from a tip, too.