I have been visiting this shrine whenever I went Ayyappaswami yathra since 1980s. Because of these contents a mini idol made of panchaloha is kept in front of the main statue and the bathing and other functions are done to it as it is presumed to be the service done to the main deity.
Infact that is how many of the traditional Mariyamman idols are prepared or made, particularly in Tamil Nadu. Mother Goddess Mariyamman Temple is in Samayapuram close to Tiruchirappalli in Tamil Nadu.