It depends…
Was there bedding? (would dilute the strength)
Does it look black and fine, i.e.totally decomposed? If so the nutrients are less water soluble.
Is it from battery hens? If so I guess it may be ok for flowers, though I am not sure about what they give hens now.
I would not use 6in for beds, better as 1in mulch, but without knowing the details, am not sure.
