This is all far too complicated. A small bar of pure gycerine soap is all you need to clean silk stuff without having to worry.

That said, in this day and age an illiterate $5-an-hour TSA will probably confuse "glycerin" with "nitroglycerin" when he or she asks you whats in your bag.

Pure glycerine soap is easy to find an any health store. I think Pears soap is one of the oldest and most widely distributed in supermarkets and such, but last I checked on the label Pears have put other stuff in it and it isnt pure glycerin anymore in there. But is maybe close enough if you dont want to do the work to find the real thing. I think Dr Bronners may also be pure glycerin.