Generate a custom zip file based on the KiwiChat ( kiwichat.github.io ). IRC client based on kiwiirc supports direct websocket connections to IRC servers
Go to https://custom.kiwichat.eu.org.
Configure your settings, simply download and it into your plugins folder.
Configure your settings in the WordPress dashboard then drop the short tag: [customkiwichat] into your page or post.
Instantly your users will be able to stay connected via IRC.