You asked about cover scents, but then talked about attractant and scent reducing sprays - 2 different things .
A drag with deer scents or vanilla, etc serve as attractants or curiosity.
Most sprays are to reduce scent already there.
Both of these can help to some extent.
Cover scents are things such as earth or fox, skunk (etc) pee used in an attempt to cover human scent. I say attempt because they flat out cannot hide human oder from a deer. Deer have the ability to process several odors simultaneously - add an oder to yours, no matter how strong and they simply smell you and the pee you added.