I made a python implementation for a different mnemonic encoding. The encoding requires user to remember words but not the order of those words.
The code is open (MIT license) at https://github.com/sancoder/noomnem
Thanks Anton. There's an interesting mathematical question of whether it's possible to make a code like this which always uses the BIP-39 words for the same key as part of its encoding, basically adding a few words as error correction in case the order is lost or confused. If the BIP-39 contains a duplicate you can add an extra word.