I don't know, but will tell anyway! I wish there was shader like Glossy Translucent, but really translucent (and not bugged!). But, with what we have at hand, we'd resort to glass or glossy (not)translucent.
Head on the first image (from top) looks like some wax or soap, but! It would be that translucent if there's more air than wax in that material. You'd better either make it 100% opaque, or make Scattering Scale much bigger, so it won't be see-through.
Second image: it's like some sort of plastic. It's better, because material is not see-through.
If you want something like human skin, then Absorption Depth should be much smaller. Something like 0.13 - 1.3 mm. I don't know exactly how much
