How to properly implement RabbitMQ RPC from Java servlet web container?

How to properly implement RabbitMQ RPC from Java servlet web container?

I'd like for incoming Java servlet web requests to invoke RabbitMQ using
the RPC approach as described here.
However, I'm not sure how to properly reuse callback queues between
requests, as per the RabbitMQ tutorial linked above creating a new
callback queue per every request is inefficient (RabbitMQ may not cope
even if using the Queue TTL feature).
There would generally be only 1-2 RPC calls per every servlet request, but
obviously a lot of servlet requests per second.
I don't think I can share the callback queues between threads, so I'd want
at least one per each web worker thread.
My first idea was to store the callback queue in a ThreadLocal, but that
can lead to memory leaks.
My second idea was to store them in a session, but I am not sure they will
serialize properly and my sessions are currently not replicated/shared
between web servers, so it is IMHO not a good solution.
My infrastructure is Tomcat / Guice / Stripes Framework.
Any ideas what the most robust/simple solution is?
Am I missing something in this whole approach, and thus over-complicating
things?
Note 1- This question relates to the overall business case described here
- see option 1.
Note 2 - There is a seemingly related question How to setup RabbitMQ RPC
in a web context, but it is mostly concerned with proper shutdown of
threads created by the RabbitMQ client.