John Holt is supposed to be the "father" of unschooling, but I don't really subscribe heavily to any gurus. I have my instincts and unschooling friends and I do what we do, and it works.
My kids are still young, being 6 and 7, they wouldn't have be achieving any great feats in the school system just yet, anyway. My technique is a combination of what I mentioned before, where I lean heavily into their windows of interest. Find cross-cirricular suggestions to pick apart the topic until the window of interest is passed, but by then, it's firmly lodged in their brain. No "in-one-ear" here. So, it's a combination of that, and being a motormouth.
I talk to them about things, all the time. Ever since they were babies, I used full sentences, and so did my family. Sure, we did some baby talk too, sometimes, but I'd also have full, one-sided conversations. I'll tell them things about stuff they never asked about, but I won't demand their attention. I'll ask them questions about what they think about things. "How do you think that happens?" Or, "do you remember how that works?" Or a random simple word problem associated with the activity we're doing.
But I'm super hands-off. They play a lot of video games. It's how they're such great readers, I'm convinced π I've always offered them educational content and supplies, though, with great success. When kids don't feel forced to learn, it's fun for them.
Their father comes from a stricter background and has in the past forced them to sit and practice their penmanship or math or forced them to do some other subject with him. Sometimes he can win their attention, but mostly he will wind up yelling at him. It's hard for him to let go. I get it. It's scared to imagine your kid to grow up to be ineligible for college. And I don't know that my kids won't ever insist on going to school. Maybe they will.
My opinion is that I don't care if they ever go to any academic institution. I honestly don't think their dad cares either, so much. It's just that old habits die hard.
He and I both appreciate and value character developed outside of a box. I am grateful every day (ok, most days, lol) I get the opportunity to ruin these kids for the normie world π