I have a whirl pool washing machine model No: white magic 650p. I thought i could clean it. so I opened the pl?

I have a whirl pool washing machine model No: white magic 650p. I thought i could clean it. so I opened the place where we load clothes. there was a thick stick like thing in the middle. i opened that too. after I opened that stick, there was a white triangular shape thing. It incidentally got dropped in the tub. I closed it and when I switched on the machine,sound comes like something is rubbing against. please help.