Retayne is used to set the color. I use a lot of red and navy fabrics in my quilting so I set the colors on all my fabrics except precuts. I soak my fabrics in a small plastic utility tub in hot water as directed on the bottle. During the soak, I agitate the fabric several times. After the soak time, I rinse the fabric a couple of times until the water runs clear. I then put the fabric in my front loader and run it through the rinse cycle. I prefer doing the initial soak by hand so I can actually see what is happening with the fabric. It is surprising to see the excess color that comes out of the fabric during the soaking. This method also preshrinks the fabric.
I have used (am currently using) Retayne that is 1-2 years old. It takes a while to use a bottle since you use such a small amount to treat your fabric. I haven't had any problems.
On precuts, I do the white paper towel test to determine if they are going to bleed.