Home Depot had a whole pallet of it. It looked reasonably fresh compared to the acid.You don't need the bucket method as acid and chlorine additions don't need to be incredibly precise. It's generally easier and safer to pour directly from the jug into the path of the strongest return, close to the pool water level to prevent splashing.
For CYA - if you added it and are reasonably confident in pool volume, assume it's there for SLAM level calculations. It can take anywhere from a few hours, to a day, to sometimes a little longer to appear via testing.
You can add salt, but also not necessary now as the SWCG won't do a whole lot to help you keep up FC. While you work through SLAM, you want to make sure you get all the way through it before considering raising CYA or thinking about relying on SWCG for FC production. Liquid chlorine is your friend, glad you were able to find a bunch.
I'm using the bucket because I'm measuring with a 1 liter glass beaker and trying to keep the beaker away from the pool.
I'll factor in the CYA in the morning's additions.
I wanted to add about half the salt at this point... partly so it's dissolved, and partly so it's out of my house. I won't be turning on the SWG until I'm done with SLAM and by then the chlorine will be high enough that the SWG should be able to keep up.
When should I add more CYA? By calculations, 12,000 gallons will use slightly more than 4 pounds for 30ppm. I added 4 pounds and it's still dissolving.
If add another 4 pounds that should put me in the vicinity of 55 to 60 ppm which is inside the range for a SWG. A bit on the low side, but I am fine with that as I just flushed 12000 gallons of water to get rid of too much CYA.