Complex sentence: The untreated airing placenta, if initially well rinsed with all excess blood/clots removed from its surface, does not have any scent, but it can become malodorous after detachment depending on the extent to which external blood products remain.
Split into simpler sentences: The untreated airing placenta, if initially well rinsed with all excess blood/clots removed from its surface, does not have any scent. But it can become malodorous after detachment depending on the extent to which external blood products remain.