We've used breastmilk to ward off pink eye before with VERY good success! When my kids were exposed to chicken pox and my daughter was only 3 months old I also expressed milk to give my toddler son to keep him from getting it.
(I figured Brianna would be safe enough from nursing that the one-time exposure we had wouldn't effect her. BUT if Evan got it the more constant contact might be too much for nursing to prevent her getting it and I thought she was too young at that point to have chicken pox) That also seemed to work well - at least, we didn't have chicken pox!
