Homebrew PCBs

Sorry to keep hounding you people with questions, but there's a decent 
amount of knowledge in here. :)

I've been told that it's OK to re-grind the regular style copper 
soldering tips, and I've been doing so. I usually spin them in a press 
and by working up to a high grit emery cloth, I can get a nice sharp, 
shiny point.

Trouble is, they turn a smoky grayish black soon after they heat up, 
and they can't be flooded with clean solder, so they don't often 
retain and release it properly while I'm using them.

Am I expecting too much, or is there an additional step I'm missing in 
prepping them? I do remember some weird recommendation of coating with 
a plumber's flux/solder and a torch, but it may not have been copper 
(or a good idea for that matter).

                            -Thanks Again!
George