Gemara: A certain mother-in-law hated her daughter-in-law. The mother-in-law told her to adorn herself with afarsamon oil. She did so [apparently, excessively]. When the daughter-in-law came, the mother-in-law said: "Light a candle," which the daughter-in-law did. The mother-in-law blew on the fire [setting the oil on the daughter-in-law’s body ablaze], and it consumed her.
Ein Ayah: That which exists on the individual level also applies on the broad level. There are enemies who outwardly interact as friends and give advice. There are also nations that give broad advice to the Jewish nation, when in fact that advice will lead to a great fire that can consume everything that is holy in the Nation of Israel.
Theoretically, using an exaggerated amount of perfume is not so bad. However, it can turn one’s heart away from internal purity and from the sanctity of Torah and mitzvot, which is the stronghold of Israel. This outward adornment fits the mode of behavior of those who strive to live their external lives according to "yafyuto shel Yefet" [the focus on aesthetics of the non-Jews who are (biological or spiritual) descendants of Noah’s son, Yefet]. When done in an exaggerated manner, it can be a step that leads to destructive situations.
We should look at the spiritual equivalent of overusing perfume. This is when the nations, who are far from our internal value system, try to entice us to make their literature and culture a major part of our thought process. When there is a confluence of the external behaviors (oil), which are antithetical to Israel’s Torah with a foreign "flame," the resulting fire will consume all feelings of sanctity within us.
Therefore, we should be careful to incorporate what the nations have to offer externally only in small amounts of that which is compatible with the Torah. This too must be done carefully. We must not rely on their advice about how to use these external matters, because they are interested in burning our Jewish souls. While they sound as inviting as the mother-in-law from the gemara’s story, the end result can be very bitter.