Using loads of carb cleaner - but I don't have a compressor.
I assume that, in order to ensure the various holes are clear, I need to eith er buy a compressor or use aerosol can compressed air to give things a good blow out.
Could you "cobble" something together using a spare tyre some tube off an old foot pump and a clamp to regulate the airflow? (very scrapheap challenge I know but it may work )