[Flerdle] The common pronunciation I hear is 'VAL-ett-ing', at least when you're talking about car cleaning. Not heard it for being a gentleman's gentleman.
I do have a fondness for the (not terribly prevalent, but permitted) alternative spelling of "queuing" that keeps the "e", resulting in "queueing"; a whopping 5 consecutive vowels.
Either works just as badly - as I said. It's always "buff-ay" here unless you're over 80 and posh or putting it on. Buff as in huff, puff, stuff and, um, buff.