I was looking for a suitable dish for this Italian made large soap bar., it is like 12cmx7cm and didn't find anything that would accommodate this luxury. So I start messing with curves and ellipsoids in Fusion 360 and this is the result. It took lot of time to come up with the right compound curves. It is scooped and sloped and shaped precisely so the water will drain from the whole surface to the sink only through the front few openings.
You can print it with 15% support and set the perimeter shells to 4, this way the spikes will be all solid.