|I can has cotton?|
According to the majority of the many articles I read, unless he starts becoming obsessive about it, or actually eating/digesting the fabric or gnawing on himself, he is simply exhibiting a soothing behavior because he was abandoned so early & he should grow out of it & will probably be ok.
Here are a couple of short articles: http://lovemeow.com/2009/09/suckling-behavior-in-kittens/
By the way, At our latest Vet visit to get his shots we learned he already gained a pound! He's really doing great; potty trained, well-adjusted, relaxed, happy, playful...really fitting in. Now, if only our other cat, Butters, would be more welcoming to him. She's very uncomfortable with the whole situation. Quite growly & hissy, in fact. She's even swatted at Ted & me. I really feel bad for her. This must be very confusing for her. I just want the whole family to get along! Time to read more articles...