Provided they are old enough, I would suggest an old technique we used to do. You generally dry them out a bit more than normal and reduce feed a bit (make sure you are already feeding enough-- many new people cut food too much and get even skinnier frogs). We used to do that for a few weeks (note you still do feed and spray, just not nearly as much-- also make sure you still have a water bowl or something to ensure they still can hydrate) and then soak them thoroughly and feed them more than they can eat. This usually works. Also, keep in mind opening the windows prior and during part of a thunderstorm will work wonders for them. If all of the above fails I hear that the Justin Timberlake cd gets all kinds of females receptive. Just a few options...
J