Use the CIM Symbol Builder to explore different combinations of symbol layers and their properties to create your desired CIMSymbol in the ArcGIS API for JavaScript.
Currently, to delete an effect, you need to open up the properties of the effect, while for symbol layers, you can simply hit the button next to it, which is more intuitive and direct:
Currently, to delete an effect, you need to open up the properties of the effect, while for symbol layers, you can simply hit the button next to it, which is more intuitive and direct: