This little gem was shown to me by the skipper of a live aboard mothership we use for remote extended charters. We are often trying to freeze fish fillets every day as well as make block ice to keep the beer cold. This little tip halves the time it takes to achieve both!
I simply went to Jaycar and purchased a small computer fan, wired it up to an old phone charger and made a little shroud for it to sit in. It took about an hour to make and saves time and money for ever after!