[snassar]

Does one really need a jailed or chrooted instance when you can just create profiles?

firefox -P <profilename>

[Izkata]

For that matter, Firefox has "open in new private window" as a built-in option on its right-click context menu for links.

Also I have a "work" container I use for this type of thing, so that's also an option in my context menu.

[chupasaurus]

The profiles have a separate history, password store, settings and extensions as a bonus.