In America you're up against a great wall of silence. Our culture makes death taboo and few overcome it.
So perhaps you should focus on communicating with the few who are comfortable with talking about death and consider them your target market.
By communicating naturally and openly with those who are receptive you'll also participate in an ongoing cultural change. Eventually, maybe even in your business's lifetime, culture will change and the taboo will fade.
Until the taboo fades at the cultural level you're not going to be successful at changing people's minds. As a business you won't have the time and exposure to others to remove the taboo.
Here's why - individuals react to strong taboos without reason. You want to persuade people with reason. But it's too late, they've already turned that off as soon as you say the word "death". (It similar to the saying that no one ever changed their mind by losing an argument. But taboo is even stronger.)
But there are people who are not uncomfortable. Find them, start with them, and just talk about it. Don't worry about others, they are not your market anyway. You can find the "embracers" in spiritual sub-cultures, pop self help bookstores, health care workers, and elsewhere. It's a disorganized group, and not a community.
If you want to be an activist (instead of a business) then you might take a personal one-on-one approach. Talk, listen, repeat. The more an individual considers death and talks about it, the more comfortable they will become. In years, the individual may lose the taboo altogether.
