A couple questions about scouring + prepping fabric for natural dye (specifically choke berry, on cotton)

I have 100% cotton, brand new unwashed fabric. My plan is to scour with hydrated lime. I am trying to find instructions on scouring with lime as well as measurements.

Does anyone know ebat is the best mordant for using chokeberry? Or something else that is actually a "stain" and not a dye.

I do know this fabric will not be perfectly colorfast, especially when washed, and the person I'm making it for knows as well. I have achieved amazing color on cotton with chokeberry, but have had it wash out very fast.

When I did it, I was doing a tea-tannin soak, alum bath, then soaking in the chokeberry dye which was prepared with about 2 parts berries 1 part water. It made an awesome shade, I am just trying to get more info about prepping the fabric beforehand to see if I can get the color to stay longer!