This idea would take a little research...but check out the pic below.
Milk jug screws into the top. Feeds down 1-3" on a larger diameter piece of PVC, which is connected with a "T" to the smaller diameter pipe below. The reduction would cause an increase in pressure through the sparge to hopefully allow for a larger spread of the water across the grain bed. The big issue with this is figuring out how to support it. My first instinct would be to grab a couple of 2x4's and press in the PVC. That would definitely have the support, but the 2x4's may drop dirt / debris / dust into the wort....which would be bad.
Anyway, just my $.02. Good luck