The BACK button or shutting the browser down, if necessary, and reloading it is the most effective solution to dealing with undesired content. Critical judgement and common sense are also powerful allies in this situation. If curiosity rather than sound judgement leads a user to a potentially objectionable site, then clearly that is something not cured by technology. These things cannot be relegated to technology but must be active participants in a young person's ability to decide between right and wrong on or off the Internet. This would not be a bad time to remember our values.
Values are our strongest allies in any trying situation.
Were we to consistently impart good, strong values to our children, so they should remember right versus wrong in the worst of situations, there would be no need for filters. This is where guardians should invest their time, as that not only would help such children optimize their Internet experience but also help them grow to be the best individuals they can be without relying on technology to restrain them from immorality. By embracing values over filters, we are expressing trust in our children, that they will decide wisely when the opportunity for misjudgement presents itself. This, over time, would help enforce personal accountability and a permanent sense of responsibility and self-respect. Nowhere in this process can we turn to cold, impersonal, valueless technology and expect that to help define the moral element of our global civilization.