Teaching unions at second level have welcomed the latest Irish Timesfeeder school list, which shows grind schools performing no better than local "free" second-level schools.
Only one grind school, Yeats College in Waterford, is among the top 50 feeder schools for third-level, according to the survey.
John White of the Association of Secondary Teachers Ireland (ASTI) said the findings came as no surprise.
"The great majority of pupils throughout the country who achieve high grades in examinations do not attend anti-educational grind schools but work in a careful, consistent manner throughout the year, thus acquiring a rounded understanding of the various subjects," he said.
The latest list shows local "free" schools topping the feeder lists for every county in the State except Dublin and Waterford.
Speaking on RTÉ Radio's Today with Pat Kenny, Mr White said the vast majority of second-level schools provided a perfectly good education where people from different social back- grounds and abilities could interact and learn together.
"The advantages of this experience go beyond academic achievement. This is what true education is about and it is in real contrast with that fostered by the grind culture."
On the same programme, John Morris of the Institute of Education said grind schools had the highest number of students gaining maximum points in the Leaving Cert. He also pointed out that the Institute - the State's largest grind school with over 1,000 Leaving Cert students - operated an open enrolment policy.
Mr White acknowledged how some parents felt under pressure to send their children to grind schools because of the media fanfare surrounding them. But he said it would be "far better if parents encourage and facilitate regular and consistent study rather than relying on the false 'magic bullet' of the grind".
The president of the Teachers' Union of Ireland Tim O'Meara said the data made "crystal clear" how "free" schools were outperforming grind school businesses.
" The Irish Timesfigures are a clear and unequivocal endorsement of the work carried out by public schools, and Irish teachers should be proud of these findings."
He also expressed concern about Department of Education figures, published with the feeder school list, which showed special needs education largely concentrated in non-fee paying schools and in disadvantaged areas.