After being so diligent with service since new, you probably let your guard down by trusting the shop to use a truly Honda-compatible ATF. "Import" + "equivalent" = Kryptonite.He said he used ATF for "import" that is equivalent to DW1.
Slipping is tough on the clutches. Don't drive it any more than absolutely necessary until the 3-times drain/fill is complete.
Take a short drive at highway speed between each d/f cycle to mix the new fluid into the large volume of fluid in the torque converter.
Dumb question, how is the fluid level?