I wouldn't recommend them mate - as when you take the hose off of the port that is connected to your hose reel - the pressure build up is increible and you get a bit wet.
I calculated for one week that the amount of back pressured water that came out of the side ports - 40L of water - over a five day period - which as you know water is money.
Stick with lifiting the reel out of the back of the van - turn the tap off on the hose reel and the water will stay compressed within your system - no water lost- means no money lost.
Johnny