Have you tried talking to the management?
My personal thought, its always better to teach n guide than to avoid..
Me n my boy stays with my mum n my uncle. My mum n myself, in fact, my circle r more of 'rough' people speaking lotsa vulgurities. Me n my mum use such words on each other often, but not quarreling, just part of our communications. During my boy's 'parroting phrase', one day, he suddenly repeat the cb word n giggled. Have to kept repeating that he shdnt b saying it cos its not a good word before he finally understands. I refrain myself from using such words not cos dont want him to hear n learn, but cos i believe the best way to teach is b an example. Nowadays, whenever my mum use the 'cb' word, he will tell my mum, 'ahma, cannot scold cb' in mandarin. My uncle is a msian n he speaks with the accent. Whenever my boy says certain words in the accent or use certain grammer wronly, in mandarin, i will correct him. N now, he speaks to my uncle in the msian style, speak to my mum in old generation mandarin style, speak to me in proper mandarin n english. My eng isnt perfect, but i will remind myself n watch my grammer n pronounciation etc..
For his sch, they use the montessori teaching method. He picks most of his eng language there. N they refrain from using negative words. Eg. Stupid. Y r you so slow. Can you b like whoever n whoever. Instead they will focus more on using encourging words.
We cant 'protect' our child from negative/wrong words or things or actions. But we can teach them right n wrong~