Barbs and tetras are egg scatterers not mop spawners. Rainbows and kilifish are mop spawners.
I've had a male and two female Rosy Barbs for about 3 months now, and though they show signs of courtship once in a while I don't think I've had any spawning.
But they are ravenous scroungers, and I don't think any eggs or fry would last long with them around.
I have 4 platies, and have seen a couple of fry from them, but none have ever lasted - and its certainly the barbs that are finding and eating them.
kribs are easy to breed, not awfully sought after so not particularly easy to get rid of.