Update: I thought sweeping from the bottom was lazy, a job in Wheeling changed my mind
Ran a 30 foot flue on a rental off Route 40 two weeks ago. Started at the top like always, and the brush kept binding on a shelf of creosote about 8 feet in. Old timer named Ray was there, he said flue was built wrong, brush from the firebox and let the rods push the junk down to you. Did it his way and got the whole run clean in about 20 minutes. Anyone else run into reverse flues like that, or know a good way to spot them before you climb the ladder?