Al Bundy wrote:
Regardless of the drying rate, Mr. Science, you will be breathing lint
and the byproducts of combustion.

I had a natural gas dryer and vented inside the home. We installed a
box with a flap in it to direct the exhaust outdoors or indoors. The
indoors hole had a fine lint filter (similar to a nylon stocking),
there was no lint coming out. I don't think there are any significant
byproducts of natural gas combustion. There certainly was no odors or
anything. I mean, it should be the same as a natural gas stove/range,
and those are obviously not vented.