I'm curious whether you all believe that the only polite way to deal with these kinds of people is to humor them or ignore them?
Maybe because I'm not someone who avoids conflict, but I actually have a lot of fun taking this kind of thing on. My DH is nothing like these people, but once in a while I get the sense that he is "man-splaining" something to me. He does have a lot of knowledge about certain things, but I've heard a lot of it before and have some knowledge of my own. So, I will just say to him, "I know that, and I feel like you're mansplaining that to me. Could you stop please?" Once in a great while, he'll get obsessed with giving me really particular instructions for how to do something. I will interject with, "Oh, would you mind also adding in the places where I'm supposed to breathe? Because I might not do it if you don't tell me exactly how and when." Yes, it is snarky and sarcastic, but I only go there when my polite/earnest requests are ignored. Luckily it's quite rare.
Yeah, but you're not married to a boorish bacon-fed knave.
Your husband sounds very different from my brother, or the woman the OP described. You had the ability to interject something. People like my brother talk longer and louder than anyone - there is no chance to say anything when they get on their rant or screed or whatever it is they're doing. It's like they don't breathe. And when you try to interject, they just raise the volume until you're frantically trying to figure out a way out of the "conversation." (A term which I use loosely, considering that the word conversation implies that both parties are able to participate.)
This goes beyond "mansplaining", which, obnoxious though it is, can be dealt with.
People like those the OP described transcend mansplaining and are in an entirely different ozone layer of goofiness.
Not to mention that people like my brother become downright hostile if you don't give them their due attention. It's hard to explain. Sometimes, it's just safer/less unpleasant/takes less time to humor them for the several minutes they go on until they wind down. If you engage them too much, or "interrupt" (and by interrupt what I really mean is "try to participate in a conversational back-and-forth;" they don't see it like that. Any attempt to do so is deemed by them a rude and pointless interruption that they have to correct by explaining - again and FROM THE BEGINNING - the entire premise of their argument and all the details they are now sure you haven't heard/understood adequately enough, because obviously you had to interrupt) them, it becomes very, very unpleasant and can turn into a hostile environment very quickly.
See, the truth is, I used to think that bullies like my brother were just cowards in wolf's clothing. So I tried bullying him back. And it worked, but it was exhausting, was extremely unpleasant, and I didn't like myself. Turning into a bully oneself is not a sustainable solution. It merely robbed me of the precious little self-esteem I had left.
Humoring him didn't work, either. It just enables them. They take it as an invitation to enlighten you.
Unless there is a middle ground, or some kind of spray you can use to get them to SHUT UP for a minute, I don't see a solution other than to acknowledge that they are just obnoxious and incapable of polite discourse, and avoid when possible.
The only other thing to do, if on the phone, is to press some buttons on the phone - that's the only thing loud enough to break through their incessant verbal chattering - and tell them the oven's on fire and you have to leave now, AND THEN HANG UP because otherwise they'll lecture you about fire safety and tell you how badly you cook and blah blah blah.
If in person, you need to fake a heart attack, and hope the ambulance crew will be kind enough to let you off at the nearest bar, or jail, since it's a crime, but worth the punishment, because jail would be more comfortable than taking any more condescending carp.