MarkC; Aluminum wire enamellers often use ultra sonic wire cleaners. I was a field service engineer starting up enamelling systems once in my life and between the pay off and the pre-annealer some of the aluminum wire systems had an ultra sonic cleaner. I did a search and found: www.hielscher.com/ultrasonics/wire_03.htm
From the explanation, it is very similar to what was used way back when (mid-70's) but I am certain that the technology and equipment is better today.
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