Could someone help me understand when which kanji is used? For example I have seen 臭い on a packet of cat sand. I can't remember where I've seen the other but I found the following example sentence on jisho.org:
It's translated as "I should follow my nose."
At first I suspected that 臭い【におい】 is used for undesirable smell and 匂い【におい】 is used for good smell but the example above seems to contradict my little theory.