Divina and Snoopy,
I am more cautious than you about this situation. I think even the best indicated remedy could cause an expulsive reaction on the stone which could be excruciating. And given that the patient is 100 miles from a hospital, an acute like that could be dangerous.
If to do that, use LM1 with the greatest caution.
If you can get a remedy to dissolve it, that would be better than surgery, but why is ultrasound not to be used? I'd advise ultrasound followed by a constitutional to prevent recurrence.