Why not start with warm water in the oven, to soften up the gunk.

I see nothing wrong with leaving the oven on for a long time with water in a pan, evaporating and making the gunk warm and moist.

I would start with that. Then use hot water on a scrubbing sponge.
It is dangerous to use a steamer. A handheld steam cleaner. Ovens have electricity in them. Maybe, maybe, if you turned the circuit off... but I don't know what all the risks are when you introduce an electric powered steamer into an oven. I imagine it is also possible that you might dissolve gunk that then drips down into places it shouldn't be..

Stay tuned for others commetns.

Here is a link that might be useful: handheld steam cleaner for grout. Not good for an oven inside.

We have Stanley Steemer come to clean and seal our foor tile and grout. They do an excellent job, and I highly recommend them.

Our Samsung induction range has a "steam clean" feature. You put in 10 oz. of water (yes, the manual says to specifically use this amount), and it runs a mini self clean cycle. I've done this, and it works well.

But like cleaning gunk out of a microwave where you put in a bowl of water (with lemon) and steam it, I'm sure this could be done with an oven. I don't know if the lemon would be safe for an oven interior, so maybe I'd skip that.

Loosey-goosey, did you know there's a cleaning forum here? If you enter "oven" in the search box below the topics list there, you'll get a bunch of threads on ways to clean your oven. The baking soda thing did a terrific job on mine, which hadn't been cleaned in years.

I bet they'd know all about how to steam clean your oven without a special steamer or a hired service.

Here is a link that might be useful: cleaning forum

thanks all.
Good points, davidro, I had thought about the electrocution factor, but not about the "gunk may slide down unwanted places" aspect.

I'll probably start with just putting a pot of hot water in there at low temp and seeing what happens; hopefully it will soften the gunk.

writer's block, thanks. I did NOT know about the cleaning forum. Thanks for the tip, I will go there. Sorry about the OT post, and thanks for not jumping down my throat about it. I am still learning the unwritten rules of GW and scared to death of making a mistake!

Oh, it's not OT at all. Just that those folks are obsessed with better ways to clean things and you get a lot of interesting alternative ways to do stuff there. No need to apologize.

Oh for goodness sakes, it is not dangerous to use a steam cleaning wand in an oven that is turned off. Foods steam while cooking in an oven. Not that much water is produced. Besides, no one is soaking the elements or forcing water into where the elements plug in. A little common sense is all that is needed.

I use steam and it's a wonderful, chemical free way to clean lot of things. Here's a video that shows cleaning an oven with steam. I got my Wagner, which looks very much like the one they are using, at Costco a year or so ago for about $50.

Here is a link that might be useful: Steam Clean Oven

Buying an expensive unit is not necessary. I paid around $50 for a Wagner system, which now sells on Amazon for less than 100, and it works just fine. I honestly think many of the machines are overpriced and don't do anything more. If they did, I would have bought one.

I clean windows -- FAST and easy (careful around seals), Solid surfaces such as granite or even laminate countertops without chemicals, disinfected stuffed animals after little ones have had a cold, it's been good on my cooktop especially around the edges where it meets the counter, and OMG what a great job it did on my leather seats in the Tahoe. It does clean grout, but it is not fast. Try it on white leather tennis shoes I think you'll be amazed.

Here is a link that might be useful: Affordable Steamer

i got the smallest cheapest steamer i could find. It cleans grout very well. It has nozzles of different sizes. It is true that the dirt it loosens has to be soaked up by a cloth right away.

So far I have not tried it in the oven, because there hasn't been any big need for it except on the oven's glass door. (the oven has catalytic coating on its sides).