I totally think it's possible for https to provide the encryption advantages it has while being able to somehow intercept ads.
It isn't. Or rather, it isn't for programs like privoxy and admuncher. And even that is not entirely correct.
If you want an ad blocker that handles HTTPS, you need a browser extension/plugin, like AdBlockPlus (yes, there was fuzz about "allowing non-objectionable ads", but that's a configuration option. I don't like that it's there, but people gotta make a living.)
For filters/blockers that work as proxies or certain kinds of winsock hooking, you can't really do much about SSL-encrypted (i.e. HTTPS) traffic. The protocol is designed not just to keep your confidentiality, but also to avoid tampering
. There is a way it can be done, and that's for the program to act as a man-in-the-middle - the same way ev0l hax0rz would attack SSL data. This means doing de- and re-encryption on the fly, messing with certificates and whatnot... and isn't really a thing you'd want done to normal web sessions.
So, either give up filtering of SSL-protected
pages, or move to a browser-based ad blocker.