What type of falling block action? There are probably more than I could care to remember!
My Stevens 44, 44 1/2, Ballards, Comblain, etc. Are easy to drop the block out of by removing the lever pivot screw, and out it all comes.
My Winchesters are another story. They take a bit more, and so don't get a complete breakdown all that often.
Really most single shot rifles, regardless of action style, get very little dirt into the action, unless you're out in a dusty area shooting. Your method of spraying them out is probably plenty good.
