Chamber cleaning started on Tuesday, 19 Feb. 
BSC10 has very robust color and staining from the original bake for strain relief. Please see attached PDF for pix.
Note the deep brown/black background color of the chamber, the yellow and orange trails and splotches and other colorful artifacts visible on the chamber’s interior surface. (Upper photos) Some concern has been expressed with regard to the quality of the brushed sections. I inspected progress this morning (21 Feb) and am satisfied that the ICC process is working as intended. Although the results are not as “pretty” or “shiny” as we would like, there is ample evidence that the surface layer is being removed (Lower photos).  Notice the change in surface color to a silver/whitish background and the absence of orange and yellow trails.