I'd first like to commend you for your sound and rational opinion about your gall bladder!
You are 100% correct, imo.
I had the same "wall thickening,...and stones", in 2009,...and let them take my GB,...worst mistake of my life,...(and I've made many!)
Drinking a ton of alkaline water before a flush helps them go SMOOTHLY,...and with much resulting 'nasties' being flushed!
Five or six good liver flushes are often all that is needed to unblock a GB,...and dissolve stones enough to pass without much tado! They say that drinking raw apple juice for four or five days before a liver flush helps as well.