Kufua basically means "beat". To say "wash clothes", you say you "beat" them. It makes sense if you think about how people wash clothes in a river.
I've also got the verb kuchachaga for "wash (clothes)" here. There's also kuchanyata "wash gently (fine fabrics)" ...
This is the dictionary I use: https://www.weltladen-moemlingen.de/download/swa_eng_dict_text.pdf ...
There is a word for kettle! It is "birika"--the same as Gazelle1596 mentionned above. for tea can. (Though I have never heard of a "Tea can" before--is that the same as a tea pot?) I always remember this because of a joke about a foreign priest coming into a kitchen and asking for a "bikira" (virgin) instead of a "birika."
The English to Swahili TUKI dictionary also gives the term "kandirinya" for kettle.
Just out of linguistic instinct, I'd say that there must be some correlation between "birika" and its equivalent in Greek "μπρίκι" (briki - roughly pronounced 'bree-kee). But then again μπρίκι could have possibly been a loan word from Turkish bürük (sort of get angry), like the coffee/tea that starts to boil in the birika! And maybe Persian/Arabic words might be the missing link between Greek and Swahili!
I repeat: The meaning was expanded to include that. My dictionary has no other word for it - there may be recent developments (or yet in the future) to either import it from English or find another Swahili word for it. So long you fare best calling a saucepan "sufuria ya..." describing it more clearly so the picture evoked differs from: https://en.wikipedia.org/wiki/Sufuria (The top right picture shows sufurias - metal pots - it was expanded to mean any cooking pots, but in the picture you see what a native speaker would associate with the word (as those are most commonly used))
https://www.google.com/search?tbm=isch&source=hp&biw=1366&bih=693&ei=hUByWp-RCZHOsAexi4GQBg&q=sufuria&oq=sufuria&gs_l=img.3..0i19k1l10.2140.3114.0.32184.108.40.206.0.0.0.103.498.6j1.7.0....0...1ac.1.64.img..1.7.495.0..0j0i10k1j0i30k1j0i10i19k1.0.WwPGIlQXwwY The third and fourth picture are the cooking pots used in Tanzania, which has then been extended to any type of cooking pots - My dictionary also has it for saucepan, yes, though that would not be the image conjured up when you use "sufuria". (In a real-life-interaction probably would probably either point to it or add something descriptive for saucepan.) I hope this wasn't too lengthy. ;)
I understand that kuosha, kufua, and kusafisha all mean different, but related concepts, but in English the verb "to clean" is a fairly broad term that includes concepts like to scrub, to wash, to launder, and others. Why, then, does it count me wrong if I translate anaosha as "cleans" instead of "washes"? Not complaining, mind you, just trying to understand what's going on.