Beags
They won't join the OTC - if they have any sense they'll join the RNR/TA/RAuxF - as they can't be mobilised before they graduate (by which time they've got their BRNC/Sandhurst/Cranditz offer and left), and the experience they get is far better, plus they get good day rates, annual camp, courses etc.
If I had my time again that's what I'd do, anyway.