The ability to cache the response of a HTTP POST request is very niche, and most of what you'll find online will tell you that you shouldn't be doing it. However if you have no choice then I can offer a possible solution as well as give you the software to avoid.
After re-installing RVM on my development machine I then found I could no longer interact with HTTPS services. This is how I fixed it.
After seeing some web based Roshan death timers I decided to make my own, but instead of just having the standard features, I added Ventrilo PTT binding support.
With the new game mode the match making queues are 45mins+, so here's how to setup your own server
