Coffee scrub is one of the most "clean" products because you make it literally with waste. Apart from the beautiful appearance and the divine scent, this will be a marketing statement. When you are using the waste from coffee machines make sure that the coffee is sand-dry otherwise you will have unwanted guests (moldering) in your product sooner than you can imagine.
You can create slightly different optics by just varying the time of the pouring the batter in the molds. The pieces at the right side of the photo above are poured immediately after the phases were blended and the batter was yet very low viscosity. This causes that the coffee powder sediments at the bottom of the mold which when you demold the pieces becomes the top of each scrub piece.
The pieces with a more uniform distribution of the coffee and a milder color were prepared from exactly the same batter but just were poured a little bit later when the batter was cooled down and had a higher viscosity and a uniform distribution of the coffee in the batter.
1- Melt phase A in a water bath between 60-65 C
2- Blend phase B in another beaker
3- When phase A is melted stop heating and add phase B
4- Add phase C
5a- For a less uniform appearance pour in the mold cavities and put the molds in the fridge for a few hours
5b- For a more uniform appearance stir while cooling down till getting to a medium trace and then pour in the molds and put the molds in the fridge for a few hours