how to test decryption of shared seed for a multisig vault

[Bitcoin]

how to test decryption of shared seed for a multisig vault

I used the script from this post

How to derive the private key associated with a Coinbase multi-sig vault address

To get the Master Private Key, Extended Private key at index 14, and WIF format of that key.
All those values  correspond to the user seed and user public key.

I need to do the same with the shared encrypted seed (and shared public key) but I am not sure I know the correct password used to encrypt the shared seed.

Looking at the coinbase multisig github they specifically state they used the BIP38 library to decrypt the encrypted shared key seeds.

Is there any way I can test passwords to decrypt the shared seed?
I assume testing should de done offline, right?

Also, I have no idea what "Extended Private key at index 14" even means in this context.  What does that mean?

Thanks in advance.

Source: how to test decryption of shared seed for a multisig vault