I tend to do sharpening and noise reduction at two stages. First is in ACR. Sharpening is to better define edges only so using Alt key while adjusting sliders I tend to mask rather heavily to avoid sharpening small details which includes noise and also apply noise reduction if there seems to be any.
Topaz denoise is pretty quick and easy to apply from PS and other software. Seems to work well most of the time.
Alternative method to mask for sharpening in PS. Duplicate background, high pass filter to get edges, denoise to eliminate ALL noise, smart sharpen, adjust layer type and opacity to taste.
If noise is not going away sometimes throwing a light texture over it will make it far less noticeable. I know, not removal but still it is rather effective for providing some camouflage.