The verify-oxp is not an OXP itself, it is a command line option and refers to the ability of Oolite to check and verify the integrity of its OXPs. For Windows, the actual usage information can be found in the 1.70 release thread, linked below:
Also note that the little bug where Oolite stops printing the debug class names in subsequent runs has been fixed in the later versions, so the logging-show-class manual fix does not need to be applied.