First - I love your quote about success
DD switched back and forth between 1 and 2 naps a day for nearly 2 months. There was no telling what she would need until she woke up from the first (or only) nap of the day. It didn't bother me, DC, or DH too much to just go with her schedule. When she's tired, she goes to sleep without any fuss and she loves her crib.
The best thing we did to promote the one nap / day: putting her to bed 30 minutes earlier at night. She still wakes up at the same time in the morning. However, she's more tired in the evenings due to less sleep during the day. Since she gets more sleep at night, she doesn't need to nap until early afternoon. She's ready for bed by 7:30, whereas she used to go to bed at 8.
Hang in there! I've found naps are something it's hard to force on or deny a kid.