The sisters have learned a few lessons from their recent debut. They are now ruthlessly efficient outfit-swapping machines. (You know, sort of like Valley Girl Terminators...)
They can now sustain swapping chains of 21 or more outfit pairs. In some cases, the sisters have completely exchanged outfits by the end.
No sister may wear an outfit that she has previously worn.
See if you can solve this one:
Take sisters EAR & TASTES through at least 21 more outfits by lending/borrowing one "accessory" (letter) at a time.
You will be revered eternally if you can end with the sisters' outfits completely exchanged. (I.e., ending with TASTES & EAR.) But this is not a requirement.
I am accepting TASER as a brand name which has come into common usage. Otherwise, all words are well-known. No need to reach for the dictionary.