Now, I would say I hate entering a correct English vocabulary equivalent. While forcing you to enter a correct one to be objective, and ensure that you can’t cheat, it might be better to ask a follow up question if WaniKani isn’t sure whether you get it right. On the-least-possible-hinting quiz, it might be along the line of, 「the said (Japanese) vocabulary is possibly used in which of the following (English) sentence?」 (It is also true that sentences can’t be translated completely, but at least it is better than vocabulary level.)
So, I would also say, be careful what you repeat or do rote memorization.
It is also true, that at least for me, audio works better than text, for memorizing this kind of stuff. Not sure about other sensation modalities.
Then, visual might be possible, if it is immovable. (Like a street sign, rather than a series of characters in a resizable font.)
Another thing I want to say, is that mnemonics don’t have to work the first time. It is far more important that you try to remember, and adapt mnemonics accordingly. (and throw away, if it doesn’t help.)
Though, at least in my eyes also, mnemonics can be in any language, and don’t have to be meaningful linguistically.