Aw, that's nothing. You should have seen the divit I dug up this weekend (flew a bunch of rounds of combat).

I use carb cleaner instead of water to flush things out. It can really blast the dirt out of the engine.

You can generally get the engine cleaned out pretty quickly with a little effort. I had one this weekend cleaned and flying again in less than 30min after digging it out of the soft ground.

Gus has it pretty darn well covered, that's for sure.

The only thing I'd actually add is that I take a step-by-step approach, trying to figure out how far the dirt got in the engine. First I pull the carb, and look down in to the engine towards the crank, and up the carb (backwards). Many times the dirt never makes it past the carb barrel. If the carb is off and there is no dirt at all in the area where the carb mounts, I spray off the prop hub area and check to make sure no dirt got in to the front bearing from the front of the engine. If that's clean, I give a gentil turn of the crank. If the crank turns smoothly and feels clean, then I just clean the carb and I'm done. This is the most common situation, and it's what I had to deal with this weekend (twice, actually). I had an impressive hole, but I managed to close the throttle before impact, and that keeps dirt from getting past the carb.

If I do that dirt got past the carb and made it down to the crankshaft, I don't turn the engine until I get the backplate off and look up the crankshaft from behind. Sometimes you'll see dirt inside the crankshaft. I try to spray it out with the carb cleaner jet. I then very carefully look at the rear bearing. Hopefully the dirt didn't make it past the end of the crankshaft. If it did, then you're in for a lot of work, as you really should get the crankshaft out of there, really wash out the bearings, etc. If I see dirt as far back as the rear bearing, then I'll pull the head and check the combustion chamber and spray out the transfer ports as well. It's not common, but I have seen dirt all the way in to the combustion chamber!