You can soak decanting supplies in a mix of water and rubbing alcohol, rinse them and let them dry. This will work for some vials but some perfumes are strong enough that the aroma will never leave (especially the caps, which are plastic). I'd keep recycled vials for your own use - don't send them out because of potential contamination. However you really should just buy yourself fresh vials - it costs like $13 for a gross of vials. Why risk contaminating a sample over an .08 cent vial?