Does anyone out there use an ultra-sonic cleaner to wash artifacts? We have one here, but it barely removes any dirt from the ceramics and glass I tried it out on. Am I doing something wrong or are they worthless? Roberta Charpentier Archaeology Lab Supervisor Mashantucket Pequot Museum and Research Center 110 Pequot Trail Mashantucket, CT 06339 Email: [log in to unmask] <mailto:[log in to unmask]> Phone: 860-396-6936 Fax: 860-396-6914