If you are the same person I remember from that other thread and you are allowed to look at printed stuff then I would:
1.) Use some export, e.g. https://wanikanitoanki.com/ and then format the .csv file in some spreadsheet software (Google Docs, Excel, whatever you got) into a list that is nice enough to look at when printed. Then repeatedly go through that list, covering one of the columns. Mark the ones I don’t know, mark them again after each run, maybe write the ones I don’t know down on a separate list. This is much faster than regular WaniKani reviews so maybe you can find some time to do that every day?
2.) Definitely enable vacation mode because I would hate to be hit in the face with a huge pile of reviews when coming back. In my opinion, the risk of being frustrated and falling off the wagon is too high. Other people see it differently, that depends on your personality. You could always switch it off on the weekend to get some of your accumulated reviews done if you can’t get it down to 0 until then. And then not forget to turn it back on after the weekend.
People also suggest the Iversen method but I’m too lazy (let’s call it busy…) for all that writing 