Hi
I offer training on day release to staff, and attach three conditions which they agree to before training starts.
If they leave while training, fail to attend the course or leave the company in less than three months then they have to repay the course costs.
Unfortunately, I don't think that would work for you since you have no realistic chance of recovering £2 - 3 000 from the average employee. Have you considered 'golden handcuffing' i.e. offering a set bonus for passing the course, payable six months after completion?
Granted, its yet more money you're spending, but you could look on it as insurance
Anyway, tuppence worth is now in and complete
Callum