I found an old dresser runner with a very dark spot in it. I tried to get it out, but it was so long ago that I can't remember exactly what I used. Probably Biz or it might have been bleach. The stain came out completely, and so did the FABRIC. So now I had a runner with a hole in it. Only the circle of fabric where the stain had been was affected, the rest was fine.
So be careful what you use on really old things. And get stains out as soon as you can!