Interesting. I didn't realize honda had gone to 9 or 10 speeds in the odyssey. My car has a pita procedure but it swaps almost all the fluid (about 1L stays unless you physically disassemble entire transmission).If it's the same as our Odyssey (and a lot of other transmissions), a proper fluid service requires multiple drain/fills (like at least 3) to actually get all the fluid out (since only a fraction of the fluid comes out during a drain, leaving the majority of it still in the transmission).
This video starts off optimistic, but I haven't watched the whole thing. Sounds like a proper 3x drain/fill with the correct fluid may be all you need.
