1. A good detergent should do the job nicely (mine were so bad I actually used Silver Duraglit and it did the job without any problems). They are stainless steel so there are no surface coating issues to worry about. Don't use anything abrasive such as a scouring cream and finish off with a wipe over with baby oil.
2. Speaker covers are still abailable from B&O but they aren't cheap. I reclothed mine but it is not a job for the feint hearted, the corners are quite difficult to get right on the top grills and you need to find the thinnest cloth available or they won't clip back on properly.
3. No idea if these are still available from B&O but other parts are such as drivers, panels etc...... worth asking.
Chris.
The use of metaphors should be avoided like the plague. They're like a red rag to a bull to me.