Which oils or techniques to get rid of dandruff?

I don't know if i washed my hair wrong as my scalp is itchy and full of dandruff though it seems this is common at first but i think i just stabbed a guess at what to do. I scooped some soda into luke warm water in the sink and dunked my head and half let it soak and half lightly massaged my scalp over about five minutes then used fresh water to rinse it. It got rid of most of the grease. No ACV. I havent found any yet but should this make a difference and how do i use it? I'm also interested in oils as i have a place i can buy them...