Zippy P > wrote:
>spray oven cleaner as far up in there as you can, then turn on the fan for
>at least a couple of hours. The fumes will reach areas that the cleaner
>doesn't and will break down the oils/grease.

But oven cleaner isn't about fumes, it's about solvents
and wiping. In this case, really nasty solvents you don't
want dripping onto your food months later.

So once you apply it, you have to remove it, too.

Vent hoods should be made self-cleaning, but that might
set houses on fire.

I like the steam cleaner idea. A better vent-hood filter
would do, too.

I bet chimney sweeps do a lot of side-work cleaning these things.

--Blair