That's pretty much what I did, but I had the temperature at 350°F, which is what I originally tempered the blade at.I don't think I do anything special, I use 2 C clamps, a small drill bit normally a 1/8 bit, or a nail, I clamp the blade down 1 inch before where the warp is and put the nail at the apex, I tighten both clamps as tight as they go. I temper at low temps (like 300), below the target temper, and only go hotter (I only go to the temp I want to temper at never over) if the warp doesn't come out. I dunk the whole contraption in water and don't unclamp until cool