I have been use a cheaper option to the metal valves.I mount my tap/value on the top of my pole just before the brush was the metal valve add a little weight. With this I have also using the Gardener P U hose as I find its the best I have used so far. I have just fitted the 5mm ID Hose lock ( black with a yellow on/off numpty) for irrigation valve the are sold at B U and come 2 at 4.99 These I bond into my P U hose between the goose neck and the brush with epoxy or Serius water proof glue (come in a silver tube.). The work very well at stopping the flow.
Hope this will help other with value options and very cheap.