The only thing that works for my whites is soaking them with Oxy Clean for a good 24 hours. I put them in the washer and turn the agitator on and off every few hours until they look white again.

Did I ever tell you about the time I over-bleached my son's white socks and when he came home from school and took his socks off they fell apart in pieces? :)

I have white towels and wash cloths from Pottery Barn. Just wash them in All. They are several years old and still perfectly white.

Use blueing in the final rinse.

I bleach all my towels and washcloths. they stay pretty white, but I've noticed if I do as Oakleyok says and soak them once in a while in hot water with Oxiclean, they really whiten up. I do the same thing, detergent and Oxiclean in the washer, let it fill and spin enough (I have a front loader)to dissolve the Oxiclean then pause it for a couple of hours.

I do the exact same thing to get greasy spots out of tablecloths or clothing (except I use warm water). Works every time.

I got mine from Costco.

Be sure yhou have all cotton towels and wash cloths....not "cotton face". Dacron is naturally sort of dingy grey, they dye it with a white color....that "bleaches" when you bleach things with dacron in them.
All white wash cloths...all cotton and clorox!

Thanks everyone. I do use oxiclean but I am wondering if it makes a difference that my oxiclean is the kind for sensitive skin and free of things that cause allergies. I used the regular kind for awhile and my Dh and two sons were allergic to it.
My cloths are all cotton, at least I thought that's what I purchased. I better double check that.
I will try soaking in the oxiclean instead of just using it in the wash cycle. Thanks again!

I use the scent free Oxiclean and it works great. The trick really is to let it soak. sometimes I soak things overnight (like for greasy spots that might be stubborn).

Costco. They come by the dozen. I use them for drying my face after washing to remove make-up. 3 years old and going strong.

Another fan of Costco wash cloths by the dozen. The ones I have are Martex. They are still bright white after six months and I don't always bleach them.

Maybe your water has iron in it. Nothing I did at my previous house With rusty well water could get anything white, especially microfiber. Luckily, now that I live in a house with city water, most of the grey has come out of the towels, even the microfiber ones! And, they get whiter when I use bleach, instead of greyer!!

Nancy