That's a strange method I've never heard. Salmon is best at a medium-rare temperture. Cooking for 50 minutes to an hour like that recipe suggests may overcook it. Plus, how do you know how hot your dishwasher runs? Every model and cycle has to vary. Way too many unknown variables for me to ever try that.
Personally I like to cook mine at a high temperture for a short amount of time. If not over a cedar plank on a grill, I like to marinate/season the salmon, then put it in the broiler for apx. 7 minutes. This should produce a nice medium rare center.