Be careful using compressed air, it's really good at pushing dirt into bearings!
Personally I use a brush and some Serpent Cleaning Gum.
For the engine, I tear it down after every day of racing or practice.
Here's the steps I use:
Remove the clutch
Cover the intake and exhaust ports
Spray off the exterior of the engine with Nitro Wash, or similar
Remove the glow plug
Remove the back plate
Remove the head
Remove the sleeve
Remove the piston
Push out the crank
Spray everything off with Nitro Wash
Inspect all parts, especially the piston and sleeve
Coat all parts with Mugen Engine Maintainence Oil, or other light oil
Make sure to coat the bearings
Re-assemble in reverse order
Following this regiment will properly maintain your engine, and you will spot problems before your engine blows up.
Hope this helps