Heck I've washed out several engines after they have ingested debris or dirt, w/o problems.

I remove the glow plug and carb, flush the engine & carb with hot water, then flush the water out with glow fuel ( it ATTRACTS water, so old fuel CAN be used w/o problems )...

Then again I flush the engine with WD-40, soak it in glow for a few minutes and flush it again with more glow fuel.

I've never have had rusting or other problems this way...