Found this on Iowa sportsman.com

This is going to sound strange but it works really well and does not stink up the house with a grease or a fish smell.

I take heavy duty aluminum foil, put one fillet into each pack that I make. Add butter, lemon pepper and a little cajun seasoning. I then place them on the top rack of the dishwasher. Run it through a complete cycle without the soap. You will have a very nice steam cooked fillet when you are done. My wife flipped out the first time I did this but now that is how we do a lot of our fish. Works really well. Saw it on a Babe Winklemann show once a long time ago