Are large gallstones safe to flush

My 79 yr. old mother needs to flush a gallstone that is 2.67 centimeters. She had a gallstone attack and had an ultrasound that measured the gallstone. The gallstone must have moved because her pain subsided after 8 hours. She is debating if she should have it surgically removed because her gallstone is so large.

Is the cure safe for someone her age with a stone that is 2.67 centimeters long?
Any difficulties? Anything to be extra careful about? She is taking a paracleanse to prepare for the gallstone cure.

I have the the cure many times (flushed 2,000) with no difficulty but the largest gallstone I had was the size of a small kidney bean.

Help! Advice please!
Thank you!