Painting shower steamers

[Soaped]

I made some shower steamers and wanted to paint them, would it work to mix mica or avlctovated charcoal with alcohol to paint them?

I did read that using witch hazel to melt menthol crystals wouldn't cause them to activate but I tried that and it immediately started bubbling so I know with hazel is out.

Should I mix the activated charcoal with the fragrance oil?

Thanks for any help.