Many eBayers are selling TCA (Trichloroacetic Acid) at strengths of 50% and even 100%.  TCA is used for a variety of skin issues including tattoo removal, scar and stretch mark removal, and removal of skin discolorations.  You'll find many websites selling TCA and many describing how it works and how to use it.

Buyers such as eBayer APER2633, frivolously leave negative comments when they are unhappy with purchases.  Many may misuse these products by not thoroughly reading the instructions or deciding to change the instructions and do it their way.  Then when they get a bad result, they complain.  Correct usage of TCA does not result in scars.  Check feedback on the eBay sellers who offer TCA.  There are thousands of positive feedbacks regarding TCA used for scar and stretch mark removal, and many are on dark complexions.  

APER2633's claim that TCA should not be used on dark skinned people is false.

TCA is used on darker complexions with good results.  Check Youtube.com, search under TCA Peel.  You'll find numerous people of Hispanic and African descent who have submitted TCA peel videos, getting very favorable results with no problems. 

APER2633 states that the instructions say the skin will turn purple.  That is false.  They do not.  She obviously used too strong of a solution without doing the patch test with 25% as instructions say.  See instructions at yavonae.com.

And lastly, instructions state that buyers are using these skin products at their own risk.  Seller has no way of knowing their buyers' skin condition, history, allergies, condition, etc.  This applies to all sellers of skin care products.

All professional sellers will satisfy displeased buyers to the buyer's liking.  Instead of handling issues between the buyer and seller, APER2633 childishly labels this seller as "Con Artist."   She hasn't learned how to be mature in her dealings with others.