I usually use what is called "Hydrolat", it is the aqueous phase of the essential oil extraction by steam distillation. It contains the volatile compounds that are water soluble. They do have a smell that is different from the essential oil but is acceptable.
The research is scant on Hydrolats, so if you are looking for skin benefits it is a bit difficult.
I usually use orange blossom water (the hydrolat of distilling orange blossoms), it gives a nice citrusi smell and a freshness for a face soap.
Another hydrolat I like is the lemongrass hydrolat, I use it for soaps that I put between my clothes, It is believed that it is an insect repellent, but soap is already that, but it gives a nice smell when I open the closet.
The hydrolats are usually stable in soaps and more lasting than essential oil, but like the later they may cause allergies, so use with care.