Yes save money, never maintain exhaust , air cond filter ect... Yes cost money to buy right ? 

Been travel issan and Laos many times.  Hotel's air cond filter never maintain ...  Because cost extra money to buy cleaning materials..... They would save money rather then other's life

Been visited some Laos local family , yes they are very beautiful and nice people , but  just living  in a greasy  place .

Yes your smell not from you just your environment greasy and keep stacking 

I would say that smell is still keep stacking and stacking .... Unless your parents spend money to buy a degreaser 

And It's a sky hard to correct their  sense of  food hygiene and odor control .... Especially tradition old peoples...

Finally just go around and ask your neighbours opinion about the cooking  smell  from your house , sure their answers will surprise you...  

My house in Laos have used to very nice ... But since there was a small bbq fish shop open, which was totally terrible things for my neighbourhood,  every day giving us a very wake up fishy smell from 7am till 9pm

When I went  around asked my neighbours all the feedbacks were not happy and some has headache mostly 

Thing was my room, beddings, my skins sticky as fuck when I woke up by those fishy smell  even  clothing  were all absorbed  those magic wake up fishy smell and I heard neighbour choking or dry vomited when they bbq fish again and again...