I just latched on to a new, no lock, 442 today. The dealer had a 642 no lock as well but I loved the looks of the black gun so I went that route. I love the looks of my 60 and 66 but it was just a change. The manual didn't specify anything special for cleaning. I use regular Hoppes and Birchwood Casey spray on my all steel guns and synethic safe on my SR9. Do I need to change with the finish on the 442?