not really sure where to put such a thread, so i just stuck it in the computer section.
anyway, i found a great way to use firefox to completely erase your firefox internet preferences, bookmarks, passwords, history and get it back on demand.
i've been using this for a while, and it's really easy (for me, at least) to do right before you get on the internet each time.
it's profiles. what firefox actually does whenever you get on is create a profile for you which saves all your histories, bookmarks, etc.
if you create a new profile, then it's as if you installed firefox on a brand new computer. NO history of anything you did on your other profiles is accessible from the other one, and you can switch freely between them (you have to close all present firefox windows before switching, however), so you could use one for all your abdl stuff, and when you leave your computer, just close the window and switch to the other profile.
it's really easy to open the profile manager, but if you don't know what to look for, then it's impossible to find it by accident (especially for someone who is computer-illiterate, like most parents of my generation).
it's detailed here: Managing profiles | How to | Firefox Help
but basically you hit windows key+r (opens the "run" window) and type "firefox.exe -profilemanager" which will open the profile manager. this will allow you to create, delete, and name profiles. so before you open the internet, just open the profile manager, and click on the profile you want, and start firefox (there's even a button to start firefox right at the bottom)
just another way to hide your stuff from people you don't want to see.
(if this method is already mentioned somewhere, then someone let me know)