Whatever they use to round the edges to make them not sharp likely caused all the dust. Most pea gravel isn't all natural and they actually have different ways to round them out. You an try to wash it off outside like the above poster said. You can also try normal soil by itself. I have no idea what your soil type is in your area, but in my soil isn't to dusty and generally stays compact enough and is softer then gravel. I also add some hay inside incase my bun wants to eat. This is a 50/50 thing as it may want to cause them to use it as a litter box, so add hay at your own risk haha. My dig box is made out of cardboard right now as I was testing to see if my bun would use it. It even has a "flap door" i was testing incase she tried throwing the dirt out, luckily she kicks it in towards the box so it doesn't come out. Gonna have to make mine out of wood so it lasts. This might be something you should think about if you do add soil so it doesn't get everywhere.
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