Don't believe that in a C150 or for that matter a C152.
During my FIC the instructor was in a steep turn right on the nibble of the stall with full power on.
His words were I have never mana-----
While saying he put a couple of reversing roll inputs in.
The aircraft flicked over the top and we were in a fully developed spin going about 3-4 times faster than they normally do. It wouldn't recover with the POH spin recovery and after what seemed ages he applied power as well as rudder and it came out not very far off the ground.
Its an optional part of the syllabus, I used to do it with my students if they wanted to but I didn't push it if they didn't. Its much better to know the danger attitudes and get the student to recover when they see them than teach the spin recovery. Most spins occur in slow stages of flight when you are so near the ground it doesn't matter how much training you have had you won't have enough altitude to recover.