The main advantage homosexuals have in public discourse about their lifestyle is that normal people don't want to lay out exactly what is wrong with that mentality and sexual practice. Yes, it is hard to address it in a sermon in a meaningful way. We should be addressing the public health consequences of the sex and lifestyle. Knowing the consequences, it would be understood why it would be hateful for anyone to promote it or accept it. Priests and ministers have to be trained on how to address it without getting into the rated X gutter.
I am Baptist and I have heard Baptist Ministers address the subject by simply calling it what they believe it is - a sin. Just like any other sin. They do it without getting into any seedy aspects of homosexuality, they are preaching to adults and adults know what homosexuality consists of.
Teaching children would be a little more difficult and would require a lot of parental input in my opinion. On second thought a church class to give helpful ideas to parents might be best and then the parents could teach their own children only when they deem the child to be ready and only in terms the parents are comfortable using with their child.