I had a somewhat similar issue (though without any safety implications) when my grandson posted stones down the spout of my pebble water feature pump.
Why are little children obsessed with stones????
He ALWAYS ‘rearranges’ the pebbles, but I hadn’t noticed his latest transformation, and wondered why the water was no longer spilling delicately over the stones. I managed to get some out, but some were really tightly wedged. I managed in the end, with the aid of some surgical forceps, which I just happened to have inherited from my Dad - no idea why he had them; he definitely wasn’t a surgeon!!
So, I wonder whether you have any tweezers or fine pliers which might work with your extraction??