Can I downgrade Jailbroken PW3

hi,
I want to downgrade my PW3 ( 5.14.1 )it jailbroken but I saw the jailbreak will be much better on older versions...
I saw a downgrader on the snapshot page but it is very old and the upstream thread is talking about pw2

and it read in other posts that it can be done through serial? is there any guideline for that?

regards