We found that 23 seconds worked the best for us. Too little, and the canes will break when you go to bend them. Too long, and the candy canes will be nothing but liquid. We also tried doing this in the stove (disaster).
It's also time to make mega-batches of Christmas cookies! I know what you're saying. "Why now? Why not at... Christmas?" Well? Woodjie had a cold and I get pickety about germy kids touching food everyone's going to be eating.