You can use to skip validation for a particular method.
In case of validation using xml file, using <actionClass>-<actionAlias>-validation.xml naming we can make the validation to work only for a particular method.
You struts.xml file configuration for excluding validation for methods also differs from struts2 documentations.
Hope you misunderstand the concept of Interceptors. Interceptors are called before and after the execution of the method.
And its the exact syntax for excluding the method from validation
otherwise you can use the solution suggested by "Anbarasu"