Assuming that this example was only a small part of a much larger area of skin, I worked on an approach which would be usable for images with hundreds of times more blemishes. My approach automated both the selection process and the "repair" process.
The first thing I noticed was that the image wasn't sharp, so I applied a variety of sharpening techniques to it. Of course, this made the blemishes much more obvious, but this is a good thing because I wanted to be able to use them to make their own selection mask.
My next step was to run the sharpened image through the high pass filter (r=6, if I remember). I then thresholded & inverted the result. I then made this image into a selection and expanded the selection by a couple of pixels to obtain this:
Next, I took the slightly sharper version of the original, turned on the selection described above, and used the content aware fill tool to automatically, fill in all the areas selected in one step. At 100% opacity, the effect was a bit too strong, but dialed back to about 60%, it looked good. The result can be seen in the following before-after animated GIF.
As you can see, this process greatly reduced many of the skin blemishes without having to manually select each one. In addition, since this process used the content aware fill tool it did a very good job of preserving the remaining skin texture.
If one needs even the less obvious blemishes to be reduced, one can partition the image into two or more sets of blemishes on the basis of the selection parameters (ie, HPF radius, threshold setting, and expand selection setting) and the content aware fill parameters, and then merge the two results - say, one optimized for weak blemishes and the other for strong blemishes. For this little demo, I didn't bother to do this.
Anyway, it's always good to have a variety of techniques in one's tool kit.
Cheers,
Tom M
PS - IMHO, the skin texture that remained after reducing many of the blackhead-like blemishes is not all that great, so I would be tempted to simply steal some skin texture from another model, or from another area on this model and fix the problem that way rather than first removing the blackheads and then dealing with the not-so-great texture that remains.