That Toledo call is a good lesson in how a duct can look clean and still be choked. One thing I rarely see talked about is the transition behind the dryer itself, especially with those flexible foil or vinyl kits that sag and get pinched when the unit gets pushed back. The crush doesn't show up from outside and the hose still looks fine, but it cuts the free area down and spikes the pressure. I started pulling the dryer out and checking that run by hand before I even hook up the gauge, since a reading tells you something's wrong but not always where.

Ammonia and a ratchet strap sounds like a torture setup, and honestly the smell is the worst part. My own seized post sat in a steel frame for three weeks because every time I opened the ammonia bottle I chickened out. What helped was wrapping the seat tube in an old towel soaked with the stuff and then bagging the whole thing in a trash bag. Keeps the fumes trapped so your shop stops smelling like a cat box. Still vents the frame though, so corrosion gets the message. Took two rounds but the post finally gave up without me gassing my whole garage. Now I just pray I never buy another bike with an alloy post stuck in steel.