I already installed Homebrew and many other apps (this is my main work machine) but I'd like to be able to create screencasts showing how to do these things from scratch, preferably on my same machine and preferably without a virtual machine. I created a new administrative user but when I login with that account and head to Terminal typing `brew update` actually starts the Homebrew update process (it fails due to permissions issues). I guess I'm looking for a way to create some sort of segregated user account similar to a virtual machine—maybe like how some electronic stores let you do anything on their floor model computers because at the end of the day they all reset. I hope that's clear! If anyone has any experience with something like this I'd really appreciate some insight. Thanks!