Used old chicken broth in a stew, but washed it out. Will it be safe to eat?
Toss it.
Old chicken is risky business. What with salmonella and other bacteria.
Next time
Note if this happens again, or for anyone else, that you don't need beef or any other kind of broth to make stew. I use plain old water, and some seasoning, salt, pepper etc. And a bay leaf or two. Always tastes great.