Larry, there are so many different ways to do this, I imagine no one solution is "best"...
I mounted my pump on the bulkhead behind the toilet raw water intake.  I put the pump switch (w/ indicator light) beside the windlass switch below the game table seat (my thinking is that you need to be there anyway to turn the windlass on/off, so won't forget the washdown pump either...).
I installed a bulkhead-mount valve for the hose on the left side rear of the anchor well and I keep the hose in a canvas sack in the cockpit locker and connect/disconnect when needed (I don't like the idea of leaving it in the locker)  plus I use it to attach to the hose when I wash the boat, thereby giving it a freshwater rinse occasionally, otherwise it corrodes up pretty fast.

That's my system anyway,  I can post a few pics if you're interested.
 
Howard

Larry - I have one to put in, but right now it is fairly low on the priority list.  The general plan is to "T" off the head intake, mount the pump under the V-birth and have the outlet on the port side of the locker.  as for the switch - my current thinking is to use a relay with power feed off windlass battery - and have a switch on the navpod at the helm (but may stick with a switch on the electric panel),  I've already have wires in the helm guard for both the pump and windlass up/down (no switches there yet).   There is also a windlass control in the anchor locker if there is enough wires in the pendant I might put the switch in there also.  I have a separate battery, battery switch & charge module under the v-berth. 

I have to pull the windlass fairly soon and re-bed (hopefully the core is ok).  I just got the boat a month and a half ago and this is the last "leaky" spot that I know of.   Next project is finish the autopilot - I'll send a write up on it with some pic's - the articles I've seen here (including yours) are all MK-II's -  needless to say my 1983 version doesn't have a swim step to mount the linear drive on.  Last night I welded up a mounting bracket (still need to add gussets)  - but this is a washdown pump thread - more later.

Les

Larry. What I did was tee into the raw water intake line with a pump. Then ran lines for and aft for wash downs. The switch is on the control panel below by the windlass switch. The fitting I use up front is from http://www.newfoundmetals.com/ I then store the 5 foot of hose in the the anchor locker. The fitting you will see on the web site fits flat and is right by the foot switches.

Our setup is similar to Lee's. The switch is mounted next to the mindless switch. We have a 5 ft hose in the anchor locker on the faucet installed there.

Our setup is similar to Lee's. The switch is mounted next to the mindless switch. We have a 5 ft hose in the anchor locker on the faucet installed there.

One more idea for Larry - Assuming you have a windlass, you can use the power from the windlass and avoid installing a switch since you will have the power on only when you are anchoring. I am not sure if you are considering using fresh or salt water to wash down.
     Salt water - you can T off of the the head salt water hose and have the water pump near the windlass motor. I am not sure how to take the hose to the anchor locker.
     Fresh water - T off of the cold water hose in the head. For this - switch or power is not needed.
     Send us some photos of your completed project.
    

 

here is a "purchase" solution for your hose garage...
http://www.defender.com/product.jsp?path=-1|10918|2303323&id=2259943

Larry;
I have posted a few pictures (for what it's worth) to give you a few ideas...
The fixture I used in the anchor locker is a bulkhead mount hose fitting with ball valve shut-off.
The wash down pump is located on the bulkhead between the head and V-berth.  The pump switch is located beside the windlass switch.
H

Larry,

As best I can understand your idea, I believe I have done the same thing on my boat.

My water connection is in the head, "T"'d off the fresh water flush intake.  I used a strainer and ran the water line to anchor locker.  I mounted my washdown pump next to the windless and took power from the windless circuit.
 
I put the switch in the anchor locker and used a 4" piece of PVC pipe to store the coiled washdown hose.

 

I was going to run the wire back to the panel, but others here prefer tying into the windlass system.  If I were to do that, I could use an 8 gauge wire, a lot less of it, and a lot less snaking around.  I was pretty surprised at how expensive that wire is (I know, it's a boat, but as a sailor I like to keep up the tight-fisted image.)
 
I haven't started taking things apart yet.  Is there an obvious place to tie into the windlass power? I want to avoid making a connection in some hidden spot that no one will ever be able to find.  If this were the house, I'd make the connection with wire nuts.  I know not to do that. Do I need a special 3 way heat shrink connector or can I put two wires on one side of a regular butt end connector?

Just came back from the boat after pulling away a few panels in the bow.  It appears to me that the path for both the plumbing and the electrical wire follow the same path initially. 
 
From under the shower seat, behind the funky "drawer," then through the compartment where the forward H2O tank is (the tubing can just sit across the top of the tank), then up against anchor locker and up to port for plumbing and starboard for electrical.
 
I hadn't realized how heavy duty the windlass wiring was.  No reason not to go right to the terminals on the windlass, is there?
 
That 8 gauge wire is pretty heavy.  Is there an issue connecting it to the 16 gauge from the pump t the 8 gauge wire?