I am a teacher and students use homophobic language. What kind of approaches should be effective to make them realize that homophobia can harm others

I teach mathematics at a suburban Toronto area vocational school. Virtually all of the students at the school have learning disabilities, behavioural issues, or some other reason for NOT attending a “regular” school. Many of the students are immature / confused / angry. For the most part, these students do not make bigoted remarks regarding ethnicity or religion. However, “fag” and “gay” seem to be common put downs – used as synonyms for stupid or unpleasant. Occasionally, I will stop the lesson and try this approach: “You wouldn’t attack people based on their skin colour or religion, so why are you offending people based on sexual orientation?”. I have also ejected students from the classroom for persistent homophobic language. This is a workplace school, so I have also pointed out that a boss / co-worker may be gay / lesbian or have friends / family who are. They may severely mess up their career by being bigoted, rude and homophobic. Any better approach?