Cover scents are perfectly fine and will not affect the results you may or may not get from wearing the pheromones.
Most persons use cover scents because they do not particular like the scent of neroli.
In terms of how many sprays and where to apply the pheromones has to do with you. Pheromones is about personal testing and growth so through finding your sweet spot one of the things you will find is which places on your body the pheromones work best for you.
Of course, if you put them under heavy clothes it will stifle the smell and diffusion will not occur and that is what you want for it to affect ppl.
This thread should assist and eventually more ladies will come in with their input. Hope this helps.