The high-school I attended used that method. I was often forced to spend significant chunks of class time teaching other students how to do their work. It was frustrating, and generally a waste of time. It made me hate going to class, because I couldn't spend my time learning, I had to dedicate my efforts to trying to get some kid who would rather be "making beats" on his desk to learn basic math.
I think a better idea would be to have high-performers help teach the kids at the middle of the pack, and leave the low-performers to teachers who have the specific skills needed to deal with their all too common behavioral problems and lack of interest.
I think a better idea would be to have high-performers help teach the kids at the middle of the pack, and leave the low-performers to teachers who have the specific skills needed to deal with their all too common behavioral problems and lack of interest.