Not directly, however it would be pretty easy to manually use a different dispatcher.
I don't have access to the source at the moment, and I can't remember the exact steps, but I think the relevant class is ThreadPoolDispatcher. If there is only one method that you want to do this for you should be able to just use the dispatcher manually, if you are going to do it for a few different classes you can write your own interceptor.
If you want more help let me know and I will give a concrete example when I am on my dev machine.
Thanks. You gave me some ideas, but an example would still be highly appreciated!
The problem is that these dispatchers all have the same Seam name, and you can only install one at a time in components.xml. How can you manually use another dispatcher?
install it under another name and manually invoke the appropriate method. You will not be able to use the nice seam annotations but it will get the job done.