There were probably multiple sizes of parafrags. I seem to recall something about a 250lb version. It would definitely NOT carry 60 of these. If it carried 60 of anything, they were "nuisance" bombs, meant to be scattered over an enemy airfield so that no operations could take place, and/or to destroy parked aircraft.
Again, not seeing much use for that.
250lb parafrags: You'd get 12 (going off a 3000lb bomb load), and you wouldn't be able to hit very accurately with them.
Say you drop a string, hit some, miss some, come around, and there's one building left up. You make a pass, but the inaccurate nature of the parafrag makes you miss... You come around again and again, but because it does not follow normal ballistics you cannot hit that single building.
The 75mm would be a lot more useful for shooting towns down than the parafrags would be.