I need to be able to be 1000% certain that they could not accidentally do anything to their normal setup since this is a once in a blue moon occurrence caused by forces unknown at this time. I cannot risk making any changes to their normal browser or laptop
The httptunnel software is an app that runs on your system and only provides the tunnel while it is running, and only for those apps that have been configured to use it. Everything else will work normally on your system and not use the tunnel.
I do recommend using a portable browser more for convenience than any thing else, to avoid having to configure, and reconfigure each time you want to use it or stop using it, and this can be any portable browser that can be configured to use a SOCKS proxy. I don't know anything about a portable IE, I don't use IE.
But I have checked and both portable Pale Moon
and portable Firefox
can be configured to use this.
One you have configured the browser to use it, it's as simple as launching the tunnel software, waiting for it to connect, then running the portable browser. When you are done, close both and go about your life.
As long as you are not making any configuration changes to your regular browser, nothing should go wrong.
As far as setting up a portable installation of the tunnel software on a flash drive, I do not know if that is possible. I was not referring to using a flash drive in my response. Perhaps the word "portable" threw you off? I only mentioned that because the browser would be self contained and any changes made to it would not affect their default browser. It doesn't need to be placed on a flash drive. It could very well sit in a folder on their hard drive, with a shortcut to it on their desktop.
I would suggest you download and try the free low speed service they offer and configure a portable browser to use it. Then you will understand how it works and the experience will probably answer most of the questions you might have about using it, and also allow you to be able to explain it better to them.