Wow, I think this is great! I am a firm believer in educating kids and adults a like about sex, in all it's various forms. I had my eldest step-daughter come back to me years later saying that she had really appreciated me talking on this subject. In the end she said the point she said that really stuck with her, was when I said, that sex could be either the most wonderful thing, or the most horrible thing that happened to you. And that I wanted her sexual experiences to wonderful, and how they would be so was making sure it she was the one in control of what was happening, by it being her choice, her being ready and prepared, and desiring what was happening. We did discuss rape, and this segment is not including that part of the discussion, as that is something so horribly, completely not your choice, or in your ability to control.
I just suggest you use a decorative item of his in a strange way, old highschool trophy dig with it to get a weed out. Or polish the table with his favorite band shirt he can't fit anymore. I don't suggest ruining the item, but using it and saying well it just sits there?!?! Decorative items give pleasure to the decorator. If your towels and soap give you pleasure looking at them, there doesn't need to be an explaination why it's not used. You enjoy looking at it, like that. My children beg to take one of my tin lunchboxes to school for their lunch. I collect them, and they can't understand why I don't use perfectly usable lunchboxes, that are soooooo cool.