Acutally, you don't really need to Push or spin the ball lightly or smoothly, it all depends "All on your hand power", And yes, bowlers like irfan pathan, Ian Bradshaw usually do it with general seam, up-right and Pace slowed down..
You can recently view the Bowlers like ishant sharma, Zaheer Khan doing it brilliantly, hope in the 2nd Test match Against Sri Lanka..