Personally, I've used the stuff before. If we can put aside the "what's in it?" argument for a moment (after all, disclosing a secret recipe means you'll be open to copycats and such) then maybe we can talk about what it does. For anyone actually interested in what it can do, and what it's worth, I'll give you my experiences.
I tried a bottle that I got from the TC Paintball in Traverse City, MI. I had two and a half bags of old paint that I had left sitting in my car for most of the winter (two bags Premium, half-bag Stinger). I would normally throw this paint away, or maybe risk making a mess of my gun by shooting it at a tree, which usually means broken paint and accuracy too poor to even practice sharp-shooting. I figured that a small bottle of this solution, that costs a fraction of the paint I was going to throw away, was worth the risk.
I brought the paint inside, and followed the directions on the Butter Balls (pretty straightforward). I purposely left some paint aside, because I figured to make sure it's worth my money, I need to make sure that the paint truly was beyond use before the treatment. I noticed that many of the balls had flat spots, dimples, and the like due to sitting on top of each other.
After letting it work overnight, I shot it the next day. And honestly, the paint shot fine. The balls were back to round shape, fed through my B2 fine, and shot accurately from my Ego. The paint was usable, broke on my target, and was pretty accurate. And just to check, I then shot the old paint that I didn't treat, and broke the very first ball I tried to fire. Even though that old paint had gotten a little better after sitting in warm conditions, it was still far from being anything I would bring on a paintball field. If the ball didn't break, it winged way off target after only a few feet. After getting sick of cleaning my barrel for the tenth time, I said "screw it." The untreated paint wasn't worth the hassle.
So, in a nutshell, the stuff did work. It took worthless paint and made it good enough to take to a field and play with, and get good results. I'm not saying that it can take 3-year-old paint and make it new again, but if you've ever thrown away a bag of paint, you already could have bought this stuff and treated hundreds of dollars of paint. Yes, ideally if you never get a bad bag of balls, you may never need this stuff. If that's the case, then fine. But if you're like me, and have a bad habit of leaving paint in your car, or not playing for a few months during winter, it will save you money. The stuff isn't a miracle, but it does recondition paintballs, which is what it claims.
If you're content throwing away paint instead of trying the stuff, then that's your business. Personally, I think that the amount of paint it can save you (thousands of balls) vs the amount it costs (less than a bag of paint) it's not too risky to try it.
Oh, and a little side note. I know a broke kid who goes to the field on Sundays and collects any unwanted paint from players at the end of the day (old stuff, dropped stuff, whatever) then he treats it with Butter Balls and uses it himself. It must work, since he hardly ever buys paint new, that I've seen.
Butter Balls Ball Conditioner is a recently developed product designed to revamp the shell composition of older paint, so it will once again be ready for use in play.
