I would think doe in estrus scents are very effective during the rut and can be used any time during the rut phase.
A buck is ready to breed after his velvet is removed and his antlers harden,so it would make sense to me that using a sex scent any time
a buck is ready to breed could be beneficial.

However, using it after the buck has dropped his antlers (assuming the season is still open) would be a waste of time.

Just my .02