What peelings techniques are available to treat pigmentation?

Superficial peels
Glycolic and kojic acid peels
Glycolic and kojic acid peels are effective in 30% of pigmentation cases. There are two forms of glycolic peels : mask and gel. The mask is the starter peel.

Salicylic, lactic and glycolic acid peels
This combination of peels has a range of beneficits, providing a powerful yet controleed effect. The combination of these active ingredients raises the concern of over-peel but this is actually extremely rare, even more so than with a glycolic peel.
The preparation containing these three acids is Milk Peel. Milk Peel is usually used for the regulation of seborrhoea and the treatment of acne. Its nature is a result of its composition : salicylic acid for its specific tropism for the sebaceous glands : lactic acidfor its emollient effect promoting hydration of the epidermis; and glycolic acid for the dissociation of keratinocytes and stimulation of the dermis. Milk Peel has, for a number of years, been the author's first choice of superficial peel.
[...]

Medium peels
Trichloracetic acid peels
Trichloracetic acid peels (TCA) remains the benchmark for a medium peel. The risk of post-peel pigmentation is common with this product, therefore it is necessary for careful pre- and post-peel management for 2 to 3 weeks using products such as SpotCream to stabilise malanogenesis. For TCA, the author recommends CosmoPeel by Dermaceutic TCA 15%, 18% with its enhancing CosmoCream, or the TCA options of 12% and 20%.
When using medium peels containing TCA; it is imperative to remember that it is certainly effective on actinic marks, but is much less so on melasma, with an almost unpredictable risk of aggravation.

Deep peels
Trichloracetic acid
TCA is not a deep-peeling chemical beyond a concentration of 30%, the risk of abnormal healing is significant.

Phenol
Phenol is the only chemical currently used to carry out a deep peel. The formula of phenol used for a deep peel is fundamentally important, and while certain practitioners claim to juggle with these formulas by cutting them and making them stretch further, there are very few who have truly mastererd the subject. This is why a reference formula is highly desirable, and the author recommends the use of ExoPeel.[...]

Specific spot peels
SpotPeel 
SpotPeel is primarily designed to treat melasma. It also has a "rejuvenating" effect [...].