Why don't you try checking out a site like
www.redclouds.com? If you are not familiar with it, it's a site for people to submit their explicit amateur pictures. Quite a few of the pictures are from swingers.
Each series of pictures has a place for you to leave comments. You aren't going to find a partner on Redclouds because odds are the folks in the pictures don't live in your town. But a sincere question about how to find partners, like the one you wrote at the top of the post, might get a respectful response. Gotta be better than the stuff on the commercial swinger sites.
And don't worry... the folks who submit their pics to Redclouds will read your comment. They're exhibitionsists! They care what people think about the pics!
Redclouds is a pay site, but very reasonable. Only $25 a year, non-recurring. If you are going to leave a return email address in the comment, be sure to create an anonymous new one on Yahoo.com or another free service.