Chaza"l and the Torah are generally very careful to speak in the cleanest language possible. When discussing the impure animals that came into the Ark with Noach, the Torah writes "Take with you seven of each pure animal and two of each animal which is not pure". The Torah didn't even want to write the word "impure" when not necessary. However, when it comes to the Yetzer Hara, we find that Chaza"l write things that sound disgusting even when said by the average person, let alone by our holy sages. For example, the Gemara writes "everyone knows that a woman is a barrel of excrement and that her mouth (allegorically) is full of blood, and yet they all run after her". When it comes to the Yetzer Hara, a person SHOULD make these unkosher desires disgusting in his eyes. A person should remember how he came from a "putrid drop" and how he is lusting after blood and excrement that will rot one day in the ground. By making the desires repulsive in his eyes, one purifies and uplifts himself out of the mud of desire.
Someone once wrote on a forum in regard to Gay behavior; "what's so sexy about dipping into the feces? What a stink!!! Human-cesspool-lovers! OOOOOFFFF…" When I first read it, it sounded revolting, but that is the way each and every one of us should learn to view all unkosher desires. How much more beautiful it is to lust for G-d instead of for these filthy cravings, as Dovid Hamelech said to G-d; "Tzama Lecha Nafshi, Kama Lecha Besari" - My soul thirsts for you, my flesh craves for you".