Within XoloX: Go to Tools > Preferences > Searching Tab

There is an option to disable the auto-complete feature.
While this will stop the feature from working , the history is still saved in the registry and when you re-enable it previous auto-completes will still be there.

To remove them see Moak's above post to edit the XoloX registry key. We have discussed this and hopefully a 'clear history' feature can be added.

So now you know of 2 methods of disabling it - one being permanent clear of search history.

-KayaMan