To be honestly, i couldn't care less about your approach and whether your mom will understand anything.
My only concern here is that others might believe this is a gOoD iDeA. That's the only reason i am commenting here. I absolutely don't care about you and your BTC.
So when you realize you're talking bullshit and making things up on the fly "jUsT uSe yOuR oS tO eNcRyPt tHe SeEd WoRdS" you just resort to petty remarks and say how you couldn't care less. Hurr durr. Just be honest and admit you're talking out of your ass.
AES is a Block Cipher which works on 16 bytes blocks.
Assuming a 12 word mnemonic code, that's 132 bit (=16.5 byte) which results in a 32 byte output. If you want to store the IV together with the cipher text, that would be another 16 byte resulting in 48 byte in total.
That's nowhere close to "100-300 gibberish characters".
A 24 word mnemonic would result in 16 more bytes (a total of 64 bytes).
Go to
https://aesencryption.net/ (something my or your mom would find on the internet), input the seed words, encrypt, count the number of characters.
Now, instead of trying to call other people out on "not getting it" where "it" equals your shitty approach every sane person in the crypto scene wouldn't even touch with a stick, learn the fundamentals. Only then, we can start talking about encryption schemes and security in general.
But you actually still don't get it because you have your head so far up your rear end and you're entirely missing the point: the point is to write down the seed words on a piece of paper and also allow family members to easily access your wallet if anything happens to you. You can either write it down in plain-text, which is not a good idea because any thief finding the paper can steal your funds, or, encrypt the seed words in some way to prevent that from happening.
Your pRoPosEd method either involves a) external/online software to do, b) storing it digitally in a file for easier copy-paste into said external software, or c) writing down 100-300 random hard-to-read Base64 characters on a piece of paper, case-sensitive, and hoping for no human error when typing it into said external software (and on paper!). My method doesn't involve external software, you can encrypt/decrypt by hand, you can write it down in easy human-readable words, it can provide plausible deniability and yes, security through obscurity (you wouldn't know whether the seed words I wrote down are encrypted (or how), mistyped, or (as long as the last word is a valid checksum) if I send a small amount of decoy crypto to that wallet, that's all you'd think there is).
A wrench attack is the only thing my method is really vulnerable to, because it's obviously crypto seed words the paper holds (hence I also made this easy way to obfuscate the seed words by mapping them to their Traditional Chinese BIP-39 Unicode counterparts:
https://github.com/mifunetoshiro/bip39_obfuscator), whereas AES encrypted gibberish gives you greater protection in this regard. A trade-off for easier and more human-friendly storing and recovering of crypto (
the very reason why BIP-39 got made, lol.
And in any case, the only reason somebody was able to crack this puzzle was because I gave out the exact encryption algorithm and numerous hints to make it intentionally easier. If I just came here and said "crack this, it's encrypted, good luck lol", absolutely nobody would be able to do it, because the possibilities I could have used to encrypt it are endless. It'd be the same as trying to brute-force Satoshi's private keys.