YOU SAID:

I don't know a smellier smell than your underarms

INTO JAPANESE

わきの下より臭いはわかりません

BACK INTO ENGLISH

I don't know the smell from the armpit

INTO JAPANESE

わきの下の匂いがわからない

BACK INTO ENGLISH

I don't understand the smell of the armpit

INTO JAPANESE

わきの下の匂いがわからない

BACK INTO ENGLISH

I don't understand the smell of the armpit