Nonylphenol ethoxylate has been shown in lab studies to increase breast cancer cells and feminize male fish.
Colored tattoos of fairies with intricately designed wings and clothes atop a simple bike also feminize a biker tattoo.
So, they will start wearing the Manly Man stuff and their hope is that, of course, that their wife will enjoy the feel of it also, and be able to slowly feminize it.