We have just started doing the Vicks on the feet and socks and it seems to work.

Also your gut health is super important to fight colds so a probiotic will help. And we also do an onion thing. We chop up half an onion sprinkle it with sugar then leave for a few hours. There will be a syrup and we use a syringe to squirt it onto the back of the throat! Works a charm :-)