paint thinner or alcohol to clean ski bases?

I clean my bases with more wax.  I feel that most of the solvents people use dry out the base material too much.  The heat involved in waxing with an iron is enough to lift minor contaminants out of the base and suspend them in the wax.  When you scrape, bye-bye gunk.

Before I wax, I make a few passes with a brass brush, then with a scotchbrite pad, always making sure to use even pressure across the width of the base.  This opens up the structure in the base and also lifts out foreign particles.

You cannot wax too much!  Most skis on the world cup are waxed dozens and dozens of times before they ever touch snow.  So much in fact, that the ski's core is penetrated with wax.

Spring and summer backcountry skiing is especially abrasive on bases and can dry out even a well waxed ski.  Using solvents, IMHO, just makes bases drier...and that's not a good thing. :

goo-gone

Quite a bit cheaper than Citrasolve, but I use both.

Solvents bad.

So is it skin goop on the bottom of my skis from last night's dusk patrol, or the pine and pollen gunk that seasoned the sweet corn?

Having rental property I have a bit of experience with cleaning stuff. If you're using citrus cleaner the best stuff by far I've found is ZEP citrus cleaner available at Maintenance Warehouse for about $10 a gallon. I don't know what it will do to bases though. The few times I've needed to clean gunk off my bases I've used paint thinner with no discernable problems.