Avodah Zarah, Chapter Three, Mishnah Three
This mishnah discusses what one must do with things that he found that are likely to have been used as idols.
1) If one finds utensils upon which is the figure of the sun or moon or a dragon, he casts them into the Dead Sea.
a) Rabban Shimon ben Gamaliel says: if [one of these figures] is upon precious utensils they are prohibited, but if upon common utensils they are permitted.
2) Rabbi Yose says: he may grind [an idol] to powder and scatter it to the wind or throw it into the sea.
a) They said to him, even so it may then become manure, as it says, let nothing that has been proscribed stick to your hand (Deuteronomy 13:18).
Section one: If one finds a utensil that has on it a picture of the sun, moon or a dragon he must destroy it, since it was certainly used for idolatrous purposes. According to the first section of the mishnah, the best way to totally destroy an idol is to throw it into the Dead Sea. In such a way there is no chance that he, or any other Jew, will ever derive any benefit from it.
Rabban Shimon ben Gamaliel states that not all utensils that have pictures of the sun, moon or dragon are forbidden. Only precious utensils with such pictures on them are forbidden, for they were certainly worshipped. Cheap utensils were, in all likelihood, not worshipped, and are therefore permitted, even though they have on them pictures of the sun, moon or dragon.
Section two: Rabbi Yose adds to the opinion in section one which stated that the idols must be thrown into the Dead Sea. He holds that it is even sufficient to grind them up and then throw the dust to the wind. The other Sages respond to him that this is not sufficient. By grinding up the idol, someone might use it as fertilizer. This method of destruction would not, therefore, prevent other Jews from violating the strict prohibition of deriving benefit from idols. The Sages bring a verse from Deuteronomy to prove that it is forbidden to derive even the smallest benefit from idolatrous objects.