I also have an HF parts washer, and got the water-based stuff. Not a fan. I don't think it cut through the crud as well, and it evaporated out, leaving a really disgusting paste in the bottom. (Yes, I kept the lid closed). My buddy got some at the same time, and he didn't have a problem with it evaporating, but he also keeps a blanket over it when not in use, so he can set parts on top.
I bought 10 gallons of odorless mineral spirits from my local parts store, and it works great. I forget now how much it cost, but it wasn't outrageous (and I'm a cheap sumbitch!).
As for the ATF to moisturize your skin...
When my dad was first diagnosed with prostate cancer a bunch of years ago, he had to fill out a form of every chemical he'd come in contact with over the years.
The doc said that your skin is just like a pair of women's pantyhose--dirt, grime and stuff won't go through it, but liquids will run through you skin just like a pair of 'hose held under a water faucet.
I've got a pair of heavy duty rubber gloves I keep at my parts washer. Don't bother with the latex or "doctor's office" rubber gloves--they dissolve pretty quickly.
-Brad