Since I started my comeback in February 2006, I've had Protec quad and a separate one for my trombone / euphonium mpc. Still, as said prior I use these only for transport NOT STORAGE. A water rinse and a mpc brush before you leave the gig will help greatly, and do not put in cases wet. The hand dryers in many washrooms do a good job of drying. I don't suppose laundry of a Protec case would be out of the question from time to time, still I'm also thinking of that "culprit" vis rubber that stains silverplate as likely has been used in cement form to bind the lining to the shell during stitching.
As for the Cavallaro ,,, there are many who are allergic to lanolin as come from sheeps wool ... I'm not one of them as I use same as skin balm and on my instrument slides.