I still have the extra dye leftover from the tie-dyed backing I made.
I should have disposed of it all weeks ago, but it was still sitting there, along with a bucket of alum water. I've heard that the alum will only last a few days, but I found this to be not true.
So, I put my ugly pink night gown into it on Friday. I just dumped all of the extra dyes into the alum bucket with it. It remained in there all day Saturday, while I was at class. I took it out and rinsed and rinsed and rinsed it out, then put it into the washer for a couple of cycles.
I like it.