So pleased to hear that Robbie is ok.
We too live with a sock, cloth, (or almost anything) gobbling thief.
who has had several visits to the vet for such misdemeaners.
The vet advised me that socks and such like can sometimes stay in their actual stomach for a long time. If they are not sick when eating it is because the sock is not covering the entrance to the intestines.
The real danger is when the object moves into the intestines and gets stuck. Provided the object is still in the actual stomach the vet can give an injection to make them sick up the entire contents of the stomach. (not pleasant but very effective & has helped Millie bring up a very thick vyleda discloth,
a plastic bag that had her treats in and also good old socks) But this only works if the object is still in the stomach.
I have learnt with Millie and soft and small fabric will pass thro ok (she chews and eats her fleece blankets
) but I have now come to the conculsion that I would rather take her straight to the vet for anything else (and suffer the £80 cost) whilst I know it is still in her stomach and can be 'retrieved' rather than live with the stress of waiting for said stolen object to hopefully appear 3,4,5 or whatever days later while running the risk of it getting stuck and having to be operated on.