I also plan on citing EV Training as one of the main benefits of chaining, so perhaps a link to my guide (when completed) would be a simple way to save any lengthy descriptions of how to use the pokeradar, etc.
Also, you missed one of the best, if not the best spot for training HP in D/P, which is surfing on Route 212-S. Woopers appear 90% of the time, while Quagsire appears 10%.
Edit: Tentacool is great for SpD in D/P. It appears 60% of the time while surfing at these locations...
Routes 205-S, 213, 218-222, Fuego Ironworks, Iron Mountain, Canalave City, Pastoria City, Valley Windworks.
Edit2: Also, it basically has the same locations in Platinum, with the addition of Route 212-S, and a worse appearance rate in a few places. Saying it can be found anywhere in Sinnoh is a pretty big overstatement, and might send people on a wild goose chase for places it actually is.