Any pointers on how to use it?

Probably you have moved on by now, but just in case you are still around:
I’ve used this plugin successfully with restricted shell RSSH.
To use the plugin you unzip it into your plugins folder and then it will appear in the wordpress plugins control panel where you can activate it.
After activation you will be presented with the extra ssh option when you go to update. Choose the ssh2 radio button and ignore the key field since you are using username/password authentication, and then click on proceed and the plugin will do its thing. Make life easier by putting your credentials in wp-config.php if that is appropriate. Check out how to do that by reading the other threads here.