I think you do that by engaging with some of the refugee organizations working with these communities to let them know this is a welcome application. As I said, there are some credible local refugee organizations that are working with these vulnerable communities.
Sometimes it's very simple things: you walk into the visa office, and there is some kind of poster talking about gay and lesbian rights in a positive way. The person sitting in that waiting room may slowly understand that Canada has these kinds of values and that it may be safe to raise this aspect. I know the UNHCR is thinking about those kinds of visual cues for the claimants in order to try to communicate to them before they have to raise the issue that this is a safe place to talk about those issues.