I suppose the average Japanese does not know another alphabetical language other than English, so even I if I managed to use katakana to match the pronunciation perfectly it would not be understood. That means it must either be translated into another language first or left alone as it is. Is there any other suggestion? (note:not a translator, just curious)
Turning this around, do you need to know Japanese to use the words like “sushi” or “kimono” in English?
There are plenty of words borrowed with their (mostly) original pronunciation into Japanese from languages other than English or Chinese and are widely used. A few examples:
パン (bread) - from Portuguese (pão)
タバコ (tobacco) - from Portuguese (tabaco)
イクラ (salmon roe) - from Russian (икра)
イワシ (sardines) - from Russian (иваси)
ガラス (sheet glass) - from Dutch (glas)
Whether to use a native Japanese word or transliteration depends on circumstances. Don’t expect the Japanese to know any specific original language but if there’s no good match you can definitely use the transliteration with an accompanying explanation of what it means. If the word becomes commonly used it might well be added to the dictionaries some years later, as happened with the words listed above.