pour boiling water

I started to watch a Teochew video and I assume it is the husband who said bu5 zui2 nam5 si2 i1 烳水淋死伊 and the guy ran away and said zang5 gung2zui2 and I was thinking what is the difference between nam5 and zang5.

nam5 gung2zui2  淋滾水｜淋滚水

to pour boiling water

澆開水｜浇开水

zang5 gung2zui2  灒滾水

to pour boiling water

淋開水｜淋开水

And after some thought, I think it is a matter of amount of water. If I were to pour a cup or a bowl, I would use nam5 and it is a bucket, it would definitely be zang5.

What do you think about what I have thought?  If you want to watch the video, click on this video link and it is at the beginning of the video.