Deck wash setup question

[rumy1]

Hi people

I am going to buy a deck wash for my Haines Signature 5.42 I have 12v power to the back so power is fine. I can do it all but the one thing I am not sure of how does it go into the water ? I can feed the hose out to the rear of the transom - do I just screw it on and have the end of the hose in the water or what ?
Does any-one have pics of their rear setup ?
I do not want to go through the hull !!!
And I am not going to buy a bilge pump for a deck wash.
I am looking at the Johnson Aqua Jet 12 Volt Wash Down Pump 19lt/min deck wash, are they good ?

Thanks for any advice or pics !!!