I have used a pole with a little tap at the bottom, let me tell you - Pain-In-The-Bum!
It was the unger hi-flo kit, comes with an inline tap. The hose gets tangled around everything, and is not easy to get at while manouvering a pole. I had only 5 litres of water, and I wasted a lot of it trying to balance everything while I fiddled with the tap!
I could understand why you might think its better to use a tap/pressure switch combination, but let me tell you, try it once and you wont be in doubt anymore!
Peter knows what he's on about on this one, a remote switch is the best way to solve this particular problem. I would have given my right arm for one on that day!
Silly