The Greek that is translated as “washed their robes and made them white” is translated in Copainalá Zoque as “have been pardoned and washed from their sins.” (Source: John Beekman in Notes on Translation, March 1965, p. 2ff.)

In Saluan the word “wash” (nombaso’i) is based on the word for “blood” (baso’), giving an interesting added layer of meaning to the concept of “wash in blood.” See the repeated word for “blood” in the translation of Revelation 7:14b: Aha nombaso’imo juba’ nu aha nu baso’ nu Anak nu Domba aijo’ da mopute’. (Source: this blog and this verse of the Saluan Bible)