When I saw the word 'blankie' I immediately thought of Bramble, who has sort of taken over a travel blanket that we used to use, as his own - it is now very holey and stinky and he trails round with it on like a little Knight's horse if he has been covered up with it!!
He seems to get some comfort from it, although he doesn't NEED to have it (it is in the back of Jeremy's car at the moment for those wet moments coming back home from the river!).
He seems to get settled best on an item of our clothing, like a jumper or something - failing which he will excavate my PJ's from under the duvet, or Jeremy's T-shirt, and snuggle down on that.
They both have favourite toys that they keep on resurrecting (empty lions and camels and other indistinguishable things with the guts removed that have been around for so long no-one can remember what they once were!!) and I think that because of their sensitive sense of smell, they should have things like that which are particularly theirs and don't go through the washer regularly ... (as long as they don't end up on your bed - yeuch !!).