I wonder if a "spray wash" with something ike apple cider vinegar might be okay. I certainly understand not wanting to stress him, such a fragile state.
You and Raggs have been quite the miraculous team. Such a bittersweet time, time to treasure, yet so difficult.
I think of you guys often. At this point, you've been letting Raggs call a lot of the shots, and he's been pretty good at showing you what he needs and what will work for him. However you two are communicating, it's pretty special.
Gentle hugs to Raggs, and you too!