At present, there is no perfect filter, nor does there appear to be one on the horizon. Filters are not parental supplements. There's nothing on the Internet requiring you to follow a clearly adult-oriented link. That's a choice users make. A number of sites are purposefully mislabelled to generate traffic to those web pages, but there is nothing preventing a user from clicking the BACK button of her or his browser.
Every modern browser has one.
There is simply no need to wait for objectionable images to fully load in the browser. Worse comes to worse, you can always close down your browser and start anew. It's not a bad time to remember our values. Values are vital allies in any trying situation. I believe not.