Quenya 

sovo-

wash

sovo- vb. "wash" (read perhaps #sov- if the verb is to be adapted to LotR-style Quenya, since Tolkiens later versions of the language do not seem to have o-stem verbs), pa.t. sóvë (QL:86)

sov-

verb. *to bathe

hwal-

verb. to wash

A verb for “wash” appearing in the phrase hwalilmien “we wash ourselves” from Eldarin Pronouns, Demonstratives, and Correlatives (EP1) from the early 1950s (PE23/126), based on the root √SWAL of the same meaning (PE23/122).