In the tutorial I used a wheelbarrow to mix in. I've since bought a 38 gallon storage bin from Home Depo. Makes it a bit easier having a larger container for mixing. They were out of 55 gal bins or I may have gotten it instead if the 38.
The last batch I made was during winter months so I used hot water from the kitchen faucet. I didn't want to freeze my hands off mixing it with water from the hose. It took 11 gallons of water to rehydrate the peat for 20 gallons of Faux-Mix® (15 gallons of peat, 5 gallons of Perlite, 2.5 cups of pelletized Dolomite Lime). 15 gallons of peat is approximately half a bale. You can use the 11 gallons of water as a guideline so you don't turn your project into a mud pie. Granted, if you get it overly wet, it will drain when you put it in pots. Just cuts down on unneeded messes.
Also in the tutorial, I used Espoma Garden Lime. I changed to another brand of Pelletized Dolomite Lime, which is available at Home Depot. Now I have a 40lb bag for the cost of the 6.75lbs of the Espoma brand.