Roch like bread but if you get a little bit of the water that the sweat corn comes in an sprinkel it on you might get some more sucesess, if you are after some nicer catches carpet bomb the swim you are going for 12 hours before with bread crumb ground bait mixed with sweat corn, choped worm, maggot an some nice blood worm that will bost your catch.
Carp are a nightmare to catch, an i can't realy recomend much to catch them unless i know what your after, crucian, ghost, mirror, etc have slightly differnt meathods.
Are you fishing a still water if so what size? Small medium or large, is it a comersial lake? or is it a river i need more info to give you a better idea mate.