The normal openDNS servers at
208.67.222.222
208.67.220.220
are only filtered for bots / malware /phishing - not for porn or other undesirables.
Milo,
This is simply not the case. Can I suggest that you visit OpenDNS and find out? You do need to subscribe, but this is free. Believe me, it is possible to do a great deal more than you state.
I mean a kind soul operating a proxy out on the inter web on ports 80 or 443 .... stick that in Preferences -> Proxies of the browser of your choice... and there you go ..... browsing freedom regained.
Interestingly, Proxy/Anonymizer is one of the categories of sites that OpenDNS can block, although I guess that entering one into the browser as an IP address might circumvent this.
SD