I haven't once seen an attempt by any site to show me a "this is what our ads would look like - we're clean, honest!" element when they detect I'm blocking.

My adblock policy (the same one I use on all friend & family systems) is extremely strict. I'm not going to whitelist your site, or any site for that matter, just to see if your ads are "safe". Your options are to show me they are DESPITE my blocking for a chance at an unblock, or prevent me from viewing your site altogether.