Wasn't there an option where you could just click on from your account that you could turn off the H pics and just look through normal pictures?
Posted under General
You can also add "rating:e" to your blacklist to protect yourself against accidentally viewing explicit posts. Maybe also add "rating:q" to play it safe. That way, you won’t get any explicit (or questionable) search results even when you don’t add "rating:s" to your searches. You’ll end up with lots of blank spaces in the search results, though, so maybe just use both.
Aside: Are you worried about "work-safe" or other issues of trouble from even downloading the images?
If so, then aren't images (including thumbnails) downloaded anyway for blacklisted material and just not displayed in the browser? They seem to display instantly when I click on my blacklists when tagging which suggests they're already in the cache.
Safebooru has been added back: http://safebooru.donmai.us/