The procedure
Chemical peel
In Jennifer Aniston's words: “A peel”
A phenol-croton oil peel is a deep chemical peel: phenol, croton oil, soap and water are painted on the skin to make a controlled wound into the dermis, which heals with a new band of collagen (PMID 33731575, PMID 3983273). Its depth depends mainly on the croton oil concentration (PMID 10626996). The statement on record does not name the peel.
Procedure page: Phenol-croton oil peel