I have a plastic soprano recorder about ten years old. Over the years its accumulated some dirt or something in the windway. it has a straight windway. What is the best way to clean it out? Could any damage be done to it during the cleaning process that I should be aware of? It also has some stuff in the bore. Would I clean that out the same way?
I approach cleaning my recorders the same way a flutist cleans their instrument because both have a stopped head joint. My recorders all came with a cleaning rod. I use a small piece of fabric, usually silk, and run this through the instrument after each time I play.
You should be careful when cleaning the windway because any nicks to the ramp (the angled section that creates the sound) can lessen the strength of the instrument's tone. Using a soft cloth, or as others have mentioned soapy water for a plastic instrument, does the trick nicely.
Because the windway itself does not effect the quality of tone production, I do not suspect it should be cleaned as often as the rest of the instrument. However, when needed, running a small piece of silk through it should do the job.
Some plastic recorders have separate blocks but most of those are glued in so removing them is not really possible. Warm/hot dishwater in the sink will do the trick. Later, a piece of card stock cut appropriately can be used to dislodge particles of food or lint that get caught in windway afterwards, or just wash it again. A clean pipe cleaner will work also, but it can leave more lint than it removes after multiple uses.
I would try a pipe-cleaner, or perhaps a cheap brass mouthpiece brush. Some mouthpiece brushes have a plastic cap on the wire though; those won't work. A pipe cleaner would probably be your best bet.
A pipe cleaner works very well. If you fold it in half it won't scratch your flute.