If you are set up for it the best possible way and healthiest for the skis is to do a hot scrape.
Doing one ski at a time-
Drip ski wax liberally on the ski and run your iron on the ski so it melts all the wax into the base.
Wait a slight bit (not to long) and use a metal scraper to completely scrape the base.
The wax should curl up or ribbon up as you scrape the ski. You may see darker colors and stuff in the wax, that is all the contaminants being pulled into the wax.
This will take the all the crap off the ski, if the scraper is sharp enough it will take filament hairs off the base too (like a bikini waxing, not that I would know), furthermore it conditions the ski base for better wax absorption for future waxing.
I usually wax my skis right after a hot wax, the normal routine since it's all ready to go.
This is better than citrus base cleaners that pull the conditioned wax out of the ski.
I only use citrus base cleaners in desperate times, because it destroys the wax conditioning that I have done to my skis.
In fact to go one step further,
It takes about 5 wax jobs to start to condition a ski after a base grind.
Good luck!
I definitely agree with Joe (and Tokogirl). This works very well and is kind to the skis.
