There is no need to stump up anything.
Sucessful applicants will get a loan that they are responsible for but that easyjet pays for. Its just a bond that is guarenteed by a bank. If you do have £23000 I think you are able to guarentee yourself though.
Reread it, its not really that bad. In comparison ryanair require a type rating at the moment through an approved TRTO and that will be £15000 of your own money.
The idea is a job that pays for your type rating but gives you the incentive to stay around.
NG