I don't have any of the brands you mentioned, Una, but I do have a few silk shirts and tops that I actually don't wear on a regular basis --- special-occasion use for clumsy me (I'm too good at the rip, tear and splash activities).
However, unless it's a hot and active day (which would be in the emergency category, as I wouldn't knowingly wear silk in that case!), I just air them out and wash or dry clean at the end of the season. I usually hand-wash with shampoo or soft soap, but dry-clean the slubbier silks to maintain the texture. If I *do* get sweaty though, I'll wash asap --- silk sets perspiration as well as other stains much worse than other natural fibres, in my experience.
Cottons, on the other hand, get Nicole's sniff test and still get worn a couple of times if they're wovens or 'lightly worn' (read: day of being couch potato or sedentary desk hand) knits.
(And yes, they absolutely ought to hire you, Nicole --- as should lots of people directly or tangentially invested in the apparel and accessories business!)
