How to get or keep whites white using a front loading washing machine?

Thanks! I have used vinegar but I put it in the tub, next time I'll do this.

Vinegar cuts the soap, that is why I put it in the softener dispenser, so that the soap has a chance to do its work and the vinegar is after the wash cycle.

But then don’t the cloths smell like vinegar?

No, they don't smell like vinegar, it rinses out on the last rinse after the softener dispenser puts the vinegar into the washer. I have never smelled vinegar in my loads when I put them in the dryer. The vinegar odor also loses it odor if you use it to deodorize anything when it dries. I use it on lots of things and once dry, like carpet for pet odors, the odor and the vinegar odor are gone when it dries.

Make sure things are color fast when you use vinegar. I learned the hard way.