clear ID Properties completely I want to add some custom properties to a bone by an if statement

if len(bpy.data.armatures[armSearch].bones[boneSearch].items()) &gt; 1:                    
    itemCount = len(bpy.data.armatures[armSearch].bones[boneSearch].items()) + 1                                
    bpy.data.armatures[armSearch].bones[boneSearch]["skName"+str(itemCount)] = shapeKeySearch                     

elif len(bpy.data.armatures[armSearch].bones[boneSearch].items()) == 1:                    
    bpy.data.armatures[armSearch].bones[boneSearch]["skName"] = shapeKeySearch

else:
    bpy.data.armatures[armSearch].pose.bones[boneSearch]["skName"] = shapeKeySearch


But when I look for the ID properties in the console there are already tow of them even though I deleted them. How can I delete them completely ?
You delete custom ID property by:

del pose_bone["ID_prop_name"]