Well, you can simple start the other way around. Post your questions on Usenet, put up a link to the posting here. If you aren't getting downvoted, and people move from Perlmonks to Usenet to answer your question, you've proved that people are willing to switch medium to answer your question. Else you've shown that people aren't willing to switch from Perlmonks to Usenet to answer your question - and hence it's unlikely they'll move from Usenet to Perlmonks to answer your question.