On 02 Odyssey, dealer did tranny flush at 77,000 miles. Then, at 108,000 I did several extractions and fills with Mityvac, not touching drain bolt. Finally, at 141,000 miles, I drained the fluid the proper way. So the bolt hadn't been touched for 64,000 miles. What interested me was that there were no detectable metallic shavings on the bolt at all....only a thin dark grey slurry. I had expected a greater accumulation of crud....guess the tranny's pretty clean.