Drain hole cleaning methods?

Take the fenders off,open the vents,get the carpets out, and remove the floor drains. Flood it with water, and use compressed air.The river of water will float most of it over the vent lips and into the cabin.
lol.
I did this before the paint went on.If you dont get the sanding dust outta there, you will be sorry.
lol
anyway, that was my solution.