Shower Steamers
These are used in the shower, and they have a combination of Essential oils that will help accomplish what you need/want. You can place them on the floor of the shower, away from the drain, but where water will still reach them, or you can put one in a mesh bag and wet it at the beginning of your shower and then hang it in a place near you. They are made without any oils so they won't provide a slippery surface.