Hi All,
the 21 day PPL is a thing of the past I'm afraid. OFT did do it and may even still advertise it but they are currently turning out students in roughly 6 - 8 weeks at best. There is a massive shortage of instructors in the US and 21 days just simply isn't realistic anymore. I would contact the FTO and take everything with a pinch of salt.
Sorry to be the bearer of bad news. I looked at the 21 day PPL not long ago but have opted for a bit longer out @ MFC in the end.
CS