I am not sure if this is relevant or not, but just thought I would mention that one of our boys (no cf) got MRSA(the skin kind) several times in a row and his doctor told us that he probably had gotten colonized with it and to get hibiclens (not sure if I spelled it right). It is soap that you buy in the pharmacy/first aid section and it is really strong stuff. You would not want to use it all the time, but the dr. said it would help "kill the colonization". And sure enough it has been over two years and not another episode of MRSA.