Anyone ever tried any thing like this?

I'm half way across the country and have seen that exact same add in my local Craigslist.
It's a rip-off just like a lot of other things on Craigslist. Agriculture has been studied more by scientists than any other subject except the medical field. If you could raise your ph simply by dumping a few gallons of liquid calcium per acre the stuff would be sold at WalMart and Tractor Supply. They are correct that liquid calcium is instantly available, and their claims that it's cheaper is banking on the questionable premise that since liquid calcium is instantly available and you apply it right when the crop needs it you don't need to apply much to make a difference in your crop. But the underlying problem of low ph will be unchanged.
Read their claims carefully and you will realize that they have been carefully written by a lawyer. Nowhere do they state any hard facts, or say that this product actually will replace the need for lime.
I tried that plot boost Liquid calcium a couple years ago. I sprayed half my clover plot with it and the other plot I left alone. I didn't do any scientific studies but the sprayed side was a bit lusher, greener and had a bit more growth. I haven't used it since, just wanted to try it but for the guys with real low PH, might be worth a try.