interesting thread.
I started flying on a Tomahawk with an instructor who was unwilling to spin it. To be honest, with 10 hours to my name it would have really scared the crap out of me so I was happy with his decision.
Just 2 weeks ago (now 35 hours) I was shown my first spin in a 152. The instructor used the entry technique described by Hugh_Flung_dung, i.e a little bit above stall speed pull back hard and a bootful of rudder. We recovered after about 1.5 - 2 turns (apparently - I was clutching the dash throughout!). We started the maneouvre at 3000ft qnh and recovered at about 2200 ft.
As a lowly student you just (largely) accept your FI`s advice, unless you have a specific reason to question it. If my instructor in the Tomy had said, "i`m gonna show you a spin" I would have said "OK".
Cheers
Rottenlungs