Q- Is the lengthy Hadith stating the virtue of Tarawih Salah narrated from Sayyiduna ‘Ali (radiyallahu ‘anhu) authentic? “Performing Tarawih on the first night washes all sins, performing on the second night washes all sins of parents” and for 2nd night another and so on for all 30 nights. 1st തറാവീഹ് എല്ലാ പാപങ്ങളും കഴുകിക്കളയുന്നു, 2nd തറാവീഹ് മാതാപിതാക്കളുടെ എല്ലാ പാപങ്ങളും കഴുകിക്കളയുന്നു", 3rd മറ്റൊന്ന് അങ്ങനെ 30 രാത്രികളിലും..?
have not come across this Hadith in any authentic Hadith collection. As you have stated this Hadith allegedly further explains huge amounts of rewards for each night that a person offers Tarawih Salah. Such exaggerated rewards are usually found in fabricated Hadiths. (See: Tadribur Rawi)
As a precaution, this Hadith should not be quoted until it can be verified.
https://hadithanswers.com/an-untraceable-hadith-on-the-abundant-rewards-of-tarawih-salah/
And Allah Ta’ala Knows best.