I read an article somewhere, but forget what it said exactly, it said either pre or post rut tended to be most effective, it was contrary to the standard perception, whatever that is... pre/post.

it works when it works if you ask me, never had much luck, have rattled in some dinks before.

They say in high doe:buck ratio areas it's less effective, so shoot some does if you have too many for sure, and it may help.

also a buck has to be within hearing distance to rattle in, in the first place.

good luck.