@GJM1
Welcome to this user forum for BT Retail phone and broadband customers.
I doubt that you will be able to do much, as water tends to penetrate underneath surface mounted components, causing low resistance paths. There is no harm in putting it somewhere warm, but many such devices are beyond economic repair when they get wet.
Assuming you are still in a contract, I would be inclined to ring BT and ask for a replacement home hub.
