Flex: BlazeDs deserialization

I'm working on a webapp built using Spring + Flex. Communication between front and back uses BlazeDS and I have a custom marshaller in order to serialize data from flex to backend as:

<channel-definition id="my-amf" class="mx.messaging.channels.AMFChannel">
        <endpoint url="http://localhost:8080/${context.root.cpanel}/messagebroker/amf" class="flex.messaging.endpoints.AMFEndpoint"/>
        <properties>    
            <serialization>
                <type-marshaller>es.onebox.flex.messaging.io.CustomTypeMarshaller</type-marshaller>
            </serialization>
        </properties>
    </channel-definition>

Is there a way to configure how use a custom de-serializer from back to flex ? I need an interceptor to modify some fields of data sent from back to flex so I think this approach could work.

I've used an interceptor for Flex using:

<flex:message-interceptor ref="myMessageInterceptor"/>

And on my application.xml I've defined myMessageInterceptor as:

<bean id="myMessageInterceptor" class="es.onebox.flex.messaging.io.FlexInterceptor"/>

And this is de content of the interceptor:

public class FlexInterceptor implements ResourceHandlingMessageInterceptor
{
private static Logger logger = Logger.getLogger(FlexInterceptor.class);

public void afterCompletion(MessageProcessingContext context, Message inputMessage, Message outputMessage, Exception ex)
{
    logger.info(inputMessage.getMessageId());
}

public Message postProcess(MessageProcessingContext context, Message inputMessage, Message outputMessage)
{
    return outputMessage;
}

public Message preProcess(MessageProcessingContext context, Message inputMessage) {
    return inputMessage;
}

}