I don’t see why all porn site addresses don’t start with “xxx” instead of “www” or at least have the start www.xxx...then whatever. Then they would be easy to filter. I wouldn’t restrict their content at all. However, if you want to access it you must type the xxx. I’m no expert, but this seems easy.
As I recall, some (conservatives) were opposed to the xxx addresses, because they thought it would make it even easier to find porn sites. I don’t know if I agree with that, because porn is very easy to find right now.
In a way it’s sad. People may have a legitimate concern about some aspect of sex, but try searching for information without being inundated with hard core porn. For example, I don’t see anything wrong with sex toys or lingerie, but turn off safe search, search those terms, and you’ll likely be exposed to porn.
I don’t actually like to give examples here, because what I think is permissible in marriage is completely irrelevant to other marriages. I don’t want to create a stumbling block for my brothers and sisters, and if they think something is morally wrong, they definitely shouldn’t do it. However, I do think it’s unfortunate that one can’t have a legitimate interest in some aspect of blessed, married sex, without also being exposed to a lot of sexual sin activities on the web.