Thanks for replying Rick. I do not think you fully appreciate the problem as stated, or I have stated it poorly. I have underexposed one and two stops, both intentionally, and otherwise. However tiny bright reflections remain. Consider the catchlight in an eye, which has the same cause. How would one avoid this by underexposing. I avoid normal blown highlights caused by the use of flash with macro, by using the camera's inbuilt highlight/shadow control which reduces highlight intensity on the RAW image. Some would say that the image is not truly RAW, but that is beside the point.
I have dificulty in defining my problem. It is like stopping sand sized grains of broken glass from appearing to glitter.
regards marty