Use better straighteners.
or that l'oreal hot straight thing or tresemme straightner spray-good luck
You can't get rid of the cowslick! I have one and they can be annoying, it just depends where yours is. You can train the hair around it or to flatten it out. Mine is about centre which makes it hard to have side parting, but i just kept parting it at the side and clipping it when wet and leaving it to dry....eventually it will naturally stay how you want it.
I have exactly same problem as you.Try using John Frieda Frizz Ease. John Freida himself produces a wide range of products suited for a range of people, and to temporary remove the frizz. Instead using the frizz on wet hair you can buy the ones for dry hair.
you leave the hair to dry and then apply the cream. Straighten your hair as usually and apply the creame when the frizz starts to come out. The cream is really easy to use as you just simply apply it to your palms and then smooth it over your hair. IOverall it is a fairly good product but the downside is that it doesnt increase the shine but it is specifically designed to remove the frizz.
There is a way of getting rid of a cowslick.
Before you go to bed get some gel or wax or whatever and put it through the cowslick and push down as hard as you can, then immediately put a cap on.
When you wake up comb through the cowlick and wear the hat around the house when you can.
For the next 7 nights wear a cap while you sleep (or anything that will flatten your hair)
Then you should see the results!
Hope this helps
my T-3 straightners work wonders on my 80's big hair and keep it straight untill the next time its washed unless it rains of course.
You can get straight shampoo and conditioner, and yeah maybe your straighteners aren't that effective.