Haha, don't know where you heard that, but you won't get that many, your not a teacher. It does actually state on the site, 22 days, rising to 25 after probation (1 year). Then its 30 after 10 years. You also get 10.5 public holidays. The bad news is the only day were guarantee'd to be shut is Christmas day.
As for the Guaranteed Interview Scheme..... Bit of a animal IMO. I personally refuse to use it, even though I can, I just don't think it gives the right impression - Your going for a senior role, you can't say the world needs to give you 25% more thinking time, it just doesnt work like that.... However if I do go for our Fast Stream again next year, I might consider it, as I'm getting so close without (i qualify due to dyslexia)