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I really hate it when that happens. These are my steps for getting sand (and other small debris) out of shoes after an adventure:
Take out the insoles if you haven't already. Lots of stuff will be trapped under/around them. I usually wash my insoles in the washing machine, I've never had a problem doing that.
Use some force to beat as much as you can out of the fabric, then shake out anything that fell out inside.
Rinse the shoes thoroughly with water. A source of pressure is best so you can run water through the fabric itself. Best is a hose, because then you can run the water both outside to inside and inside to outside.
Let them dry thoroughly. Use a fan to speed this up if needed. Leaving them out in the sun or in a heated area to dry isn't recommended as this can damage both the fabric and the other material of the shoes.
Once they dry beat them together again. If more stuff comes out, repeat the process.
The only downside to this is that your shoes are wet and out of commission until they dry.