You'd be drilling a hole into the center of the pipe plug that you just glued into the inlet of the Bassett valve. While I agree with most of these guys in that dry is better, the water does take some of the ringing out of your ears after a long cruise, and it just may help you avoid a ticket since you are at least trying.
Anyways, your ultimate goal is to keep the water from overcoming the Bassett valve at idle and a little above. The headers should be dry at idle and you should have no more than a mist and steam at any other time. If you ever see raw water dumping out, you need to cut down the flow more. I'll see if I can find a pic or a schematic of my electric setup. It's pretty simple. It basically consists of a readily available 12v electric solenoid (continuous duty cycle) a Bosch 20/30 relay, a junction block, either a MSD RPM activated switch or a window switch, and the necessary RPM pills. The cool part about it is that you can set it up (with a window switch) so you have water flow from 2000 up to whatever, but it will automatically kill the water above a certain RPM so you can still make your power if you are racing someone or just screwing around.