NEVER EVER in a million years would I say "Geez, you ate the meal, can you lift a finger and help clean up every now and then????"
Nor would I ever say, "Could ya just put the iron away since we all use it?"
I just go and get it. Which, by the way, I've pretty much dealt with via a suggestion here on this site... I just bought another. Now, she'll eventually take that one too, but I'll deal with that in the same way. As a matter of fact, I didn't say anything about the bottle brush incident. I simply waited until she walked out and discreetly threw it away. Yeah, I did it with a massive eyeroll, but so what.
Why wouldn't you say some of these things? Sure OP, It's a lot easier to let someone frustrate you and then be pissed, passive aggressive, roll your eyes, etc, than actually communicating with them. But given your current situation, that's not healthy behavior or good modeling for the kids. An admonishment to "lift a finger and help clean up" obviously won't work, but "could you put the iron away since we all use it" is totally reasonable. Families under one roof have to communicate, end of story. Now, if you continue to try, and it gets ignored, you have my sympathies. But as some other posters have pointed out, if you're that miserable, it's time to pack up the brood and go. I'm willing to bet there's some less than ideal housing options that would still be more appealing than your current situation, and I bet your MIL would welcome her freedom/privacy back. Get creative, get your DH on board and move forward.