Small Engines (Lawn Mowers, etc.): Cleaning out the valve guide in lawnmower engine, briggs and stratton, valve guide

Question
what is the best way to clean out the valve guide at the top and bottom in a briggs and stratton engine?  It is encrusted with exaughst residue.  I understand sandpaper is not good, but I could not fit a wirebrush into it.

Answer
If you are cleaning the port, I would find a plumbers wire bursh.  The brushes are round and a 1/2" and 3/4" brush will fit inside the ports.

The valve guide itself is best cleaned using the Briggs valve guide reamer and associated tools to ensure you are straight when reaming the guide.

I would not recommend sandpaper unless you are completing rebuilding the engine and will be able to wash the block in a solvent tank.

A Dremel tool and the wire brush accessories may work also.
Let me know if this helps.
Eric