I use virtual machines via VMWare for these scenarios. Not only I do not think VMs are PITA, but actually, VMs have become integral part of my development workflow, way beyond Esri usage.
Whenever I need to test something out and do not want to clutter any existing environment - I just spin up a clone of one of my development machines, do my job, and then I can delete the VM and forget it. Other environments remain intact. Once you learn to use snapshots and clones effectively, you will not want to look back.
It is also VERY useful for testing your applications under different environments and configurations.
There is of course some inherent cost to maintain those virtual machines (e.g. installing updates, updating your development tools etc. may need to be done multiple times), but again, once you figure out how to do that effectively, you can keep this cost very, very low. For example - I have my base development environment set up and all development machines are derived (cloned) from it.
Another thing is not to forget about licensing issues. For some software, there may be licensing restrictions regarding whether you may have multiple installations of a single license in virtual environment.