I dont think sillage has got anything to do with the body chemistry. It is more to do with the ingredients of the perfume. Probably i feel that you need to know the ingridents that causes the sillage. For example something like rive gauche has got a great sillage. Probably it is due to the patchouli present in it. So the point is that you need to look for the ingridents that provides sillage.