Fraxel Laser or Repair for Clogged Pores?

If you have clogged pores and "white soft gunk" under your skin, you should first be seen by a dermatologist to diagnose and correct the problem
This could be easily corrected by some form of acne treatment, extractions topical acne meds, IPL Blue light, etc.

You are jumping the gun asking for Fraxel Re:Pair when there are other less invasive, less expensive and more effective treatments are available.
You should consult with a dermatologist who would put you on a therapeutic regimen. Nearly all of us would recommend a Retinoid to be used at night. Retinoids get into the pores and unclog them; you could not have drawn up a better drug for your problem. Use of this medication should be individualized for your skin type, tolerance and skin sensitivity.
Benzoyl Peroxide should also be part of your routine. Incidentally, one thing most people do not know about BP is that it was developed not for acne, or even medicine, but as a way to bleach flour. Benzoyl Peroxide is antibacterial, anti-inflammatory, and also opens up the pores. In fact, a new drug is on the market called EpiDuo. EpiDuo has Differin in it ( a Retinoid) and Benzoyl Peroxide. The Retinoid opens up the pore and the BP agent further opens up the pore, crawls in, and zaps the bacteria.
The third and last useful agent that opens up pores is one used back when I was a teenager: salcylic acid. In fact even way before that since the great Hippocrates wrote about this product. Salicylic acid is derived from a willow tree. It is the prototypical Beta-hydroxy acid in which the hydroxyl group (-OH) is adjacent to the carboxyl group ( -COOH). Salicylic acid, of course is related to aspirin. Sal Acid can penetrate into the follicle and dislodge the comedonal plug you are complaining about. However, it does not kill P Acnes. Sal acid is less effective than Benzoyl Peroxide but it less irritating and less likely to cause an allergic reaction.
Two other modalities which will hope tame your problem of clooged pores would be peels and microdrmabrasion. A recent study (2009:35 by Garg et al in Dermatologic Surgery compared Sal Acid peels with glycolic acid peels and showed that the former was somewhat more effective. This is most likely because the glycolic acid does not penetrate as well into the oily mileu of the pore.
As far as microdrmabrasions, I would recommend a medical grade microdermabrasion and not waste your money on what you would find in a so-called medi-spa.
A good dermatologist should be able to set you up with a regimen enlisting some ( or all) of the above. More aggressive modalities such as Isolaz, Smoothbeam, or Fraxel can supplement this, but this treatment should be the cornerstone of any "plugged pore" treatment. Otherwise you will be back to where you started with your own personal recessionary spiral.