Is it true that if you put lemon juice or/and vinegar in your hair while in the sunlight it bleaches hair?

Apparantly or alkali liquids eg vinegar lemon juice have a bleaching effect but i heard from someone else that it makes your hair soft but it doesnt bleech the hair. I really want to have some blonde highlights in my hair i would go to the hairdresser but would like to know if there is a cheaper alternative.