Have you ever used teaching others as a technique for learning language?

I'm not talking about an entire language necessarily; even just a a single concept will do. I'm actually writing a Tagalog grammar book to learn Tagalog grammar better, which is way over the top I suppose. But how about explaining something to a toddler as suggested by the Feynman Technique? 

1. Choose a Concept

2. Teach it to a Toddler

3. Identify Gaps and Go Back to The Source Material

4. Review and Simplify (optional)

Hmm..this is an interesting technique and idk why I haven't heard of this theory(or however you may call it)

I mean...I sorta get it...but I think you should be really confident in your knowledge of the concept.

Cause hey, maybe I can teach it to a toddler..but what if what I thought was correct is actually wrong or I presented it wrongly? :/ 

All the little bits of languages I have acquired have been this way. I studied Spanish and a year of french when I was very young.

A large part of my graduate school experience involved teaching undergraduates, and there's really no better way to learn than having to teach, because you're forced to broaden your scope, and yet at the same time, achieve mastery of material. The most challenging part of teaching is when learners start asking very "basic" questions, which makes you start questioning all your assumptions, and then go back to basics to refresh all the information you have forgotten.

On the note of teaching languages as a form of learning, one of the more experiences that actually improved my Mandarin/Chinese tremendously, was when my Mandarin teacher forced me to (in)voluntarily tutor one of my classmates who was failing in Chinese. I had to explain a lot of things to her in simple terms, and that really reinforced my basics. 

I asked a student to trade hours with me so I could learn Korean. I taught her English for 2 hours and she taught me how to read and write in Hangul for 2 hours. I don't think I'll ever try to teach Korean so I can learn it though. I feel like it's a blind leading the blind kind of scenario.