In my experience with trying to meditate to rhythms it takes fifteen minutes to half an hour before you really notice a significant difference to meditation without it.

Also, "should" is not really the right word to use here - I would go with "might".

What I mean with that is that this isn't like a pill whose are chemicals will do its on their own after consumption, with or without thinking about them. It's an effect that is produced through a sensory interaction with the brain. As a result, how one consciously attends to that interaction has a huge impact on the effectiveness.