In two houses I used to own, I experimented with venting an electric
dryer into the house.
I did this in the winter, in climates that had snow.

In one case I probably got away with it, due to the size of the house
and its very old age. It leaked air like a sieve. Consequently, the
air changed frequently and the vapor likely didn't collect anywhere.
My only problem was lint.

In the second case, the house was 1,000 square feet, and new and
therefore well sealed (mostly). I had a family of rout. This was a
complete failure. The dryer ran very long, since the incoming air to
the dryer was very moist. I had visible moisture in the air after two
loads of laundry, heavy condensation on the dual-pane windows, etc.
There was a build-up of ice on the insulation that covered the attic
access. This was in a high-altitude and very dry climate. I conclude
that you can destroy your house by rotting it, if you have too much
moisture for the size of the house.

Moisturizing your house by using the dryer might work, but you may be
putting large amounts of moisture into the air in a very short length
of time, saturating the air and causing the problems listed above.
Maybe if you do one load on any given day, have a very small family,
large or leaky house, etc., you could get away with it.

If I find myself in a cold climate again, I would pursue a heat
exchanger instead of indoor venting.

As for the gas dryer/monoxide problem: I've never had a gas dryer, nor
a gas room heater of the non-vented type. I would like someone to read
their owner's manual for a non-vented gas-fired room heater, and let us
know the warnings associated with it. While CO might not be a problem
for a properly working heater, I have to assume that there is either a
buildup of combustion products in the room, or the instructions tell
you to crack a window or something. To my logic, it seems impossible
that you could run a heater indefinitely, in a cold climate, in a
well-sealed house, and not expect problems.

IF these assumptions are not correct, would some knowledgable person
please reply with an explanation (as opposed to the useless RS-type
responses that make statements with no support).

Thanks.