[siculars]

Wouldn't one simply use one specific browser, say either safari or firefox or chrome, and only that browser for their... unsavory activities? I think that is a great way to keep accounts separate and keep "bad" sites from knowing about "good" sites and vice versa. Just saying. Not that I partake in any such unsavory activities.

[user-id]

For testing purposes I use Chrome's "Users" feature to keep an extra profile with no extensions installed handy.

The same could be done for a "Porn" profile too I guess, sand-boxing any history, extensions and bookmarks to that profile. You could even associate tie it to a Google account for portability.