Can someone explain how to really use on of these?  I've done a bunch of reading on it and can't find any real hard info on it.  I'm looking for time and psi and the best I've found is to run it at 4 psi for 5 minutes and bump it up 2 psi every 4-5 minutes until you get to 12 psi.  Then check your carb and see if it's what you want.

I kinda thought this would be better than force carbonating, but it seems like there are no guidelines on the stone.

You are force carbonating.
I have used it with varying success. I dont think its the stone thats at fault, I think its my process.

I stuck it on the end of the gas inlet tube on my corny. Set it to 5 psi. Let equalize, wait a few minutes, remove the gas, bleed the pressure from the keg, reattach the gas, bump it to 7psi, repeat bleeding. I did that until I got to what ever volumes of co2 I was looking for.

I'm sure I will get the process down as I use it more. It does work, you just need to find out what works for you. I think its a much better method than the shaking/rolling method.

 

In my experience with the shaking and rolling method, I never could dial in the CO2 right. Was always over/under carbed. It just was never where I wanted it to be. With the carb stone ive had much better, more consistent, more predictable results

This



carb stones a waste IMO.



BTW 5 minutes for "most" beer at 30psi once cooled works well.



 

It does the exact same thing just a little slower.



 

I force carb in my kegs with 30 PSI once cooled for 2-3 days. Back the pressure down to 10 PSI and serve. Never had any beers under carbed or terribly over carbed either.

Sure, if by getting the job done, you mean just getting CO2 in suspension in beer, then yes, it does the same thing. When I am shooting for a specific volume of CO2 I havent had any luck with the 30psi method. I'm sure its just me, and how I am doing it. But the carb stone does the trick for me.
I have a spare corny lid that I am going to convert to a carb stone lid so I can just swap that lid from keg to keg for carbing.

There are many ways of getting it carbed. Everyone has a method they like best. I like carb stones.