I have been reading a lot about a product made by eastwood that looks like it will fit the bill. I have used in all off the nooks and crannies that I can't reach any other way. The extension nozzle tubing makes it real easy to get those hidden spots. Take plenty of time to put a tarp down below your work. It's messy.
http://www.eastwood.com/internal-fra...nozzle-qt.html 
