I want to send it and forget it. The http rest service call I'm making takes a few seconds to respond. The goal is to avoid waiting those few seconds before more code can execute.
I'd rather not use python threads
I'll use twisted async calls if I must and ignore the response.
You are going to have to implement that asynchronously as HTTP protocol states you have a request and a reply. 
Another option would be to work directly with the socket, bypassing any pre-built module. This would allow you to violate protocol and write your own bit that ignores any responses, in essence dropping the connection after it has made the request.
How can I make an http request without getting back an http response in Python?