Carlos,
I’ll second the above comment – there are many warnings about using this in a production environment. If Microsoft say don’t, I think its fair to say that you shouldn’t!!
I’m in a similar situation with a large number of suspended instances (20 million+) and we are using a custom WMI script to clear these messages down. Its taking a while, but its getting the job done.
If you can advise what type of messages are suspended, I’ll modify our WMI script for you to use.
Regards, Nick.