There are a number of ways to set up SSS through cycles using each of the existing nodes in the Material Room.  The only node that cannot allow Subscatter scaling is the PhysicalSurface root, I assume that the scaling is fixed at 1 which means that each of the individual RGB radii needs to be set at lower values to control the self glow.  If your radii values are too high, the combined color expressed is a shade of light grey.  I've been using the CombineRGB node to check how SSS will be expressed on the skin and connect it to the Subsurface Radius channel of either the SubsurfaceScattering or PrincipledBsdf nodes.  I came across a chart of Subscatter Radius values that was scientifically determined and published.  It may be worth perusing.