You can try using Scene 3D > Mesh Model > Smoothing Tool, but I think you are unlikely to get the result you want even on the noise removal setting. To get this nice, I think it would need to be manually meshed with Zbrush or similar or scanned better. The sample image shows that the object does have surface details, so if you can capture it at night using a cross-polarized setup on a stick, that would be great. This is possible I once scanned a 5m-high tree like this. But I can see from the image that the highlights have completely blown out in a lot of places. There is only so much that can be achieved with settings if the input data is not optimal. You might also have some luck by just simplifying the model to roughly the number of triangles you can see the original is made up of; it’s unlikely to work but worth a try.