What is this, lol, a site called "cryptosec" advises people to use this crappy cipher to protect their seed - what a joke! Even Caesar cipher would be better in this case, because an attacker would have to spend a few miliseconds to bruteforce it.

If some newbie is reading it and thinks it's a good idea, this can easily lead to lose of money in the future, because the method proposed is not encryption, it's just a very weak attempt to hide the seed. Do not use any methods you read from random sites on the Internet and do not invent your own schemes, instead research strong cryptography if you want to truly protect your secrets.