Wow, that's amazing. I work at a nursery and we have Cereus peruvianus, that bugger sounds a lot like yours. Must be 10 foot tall. Flowers are at about 7 foot. Would never want it to topple. When I was young I cut off a San Pedro Cactus at the base. I suddenly realized that it was falling towards me. I put the big fat saw over the top of my head and it bounced off the saw. Ah youth.
