How to remove the variable value with JSTL?

Question

I am testing to clear a list of objects that is passed to JSP, and run the command below:

<c:remove var="lista" scope="session" />
<c:out value="${lista}"></c:out>

But when I call the page with JSP, I find the memory address of the list that should have been deleted and normally fills the HTML elements with the attributes of the objects that are defined in the list.

EDIT

I am using a tag created by me, can it influence? (object contains list):

<ec:form beanName="objeto" controllerUrl="/parametro1/parametro2">

Whereas if I pass by removing the object with:

<c:remove var="objeto">

Bursts a NullPointerException.