baking soda and ACV mix.... not working?

So I've been dreading for about 2 weeks now, natural and twist n rip mix, and have tried the BS, ACV mix a couple of times..... Im doing 3rd of a cup BS, with 3 drops of tea tree oil in a big stew pot, pouring it on my head, leaving it 10 min to soak in a towel before rinsing it with ACV.However my hair is still coming out greasy afterwards and I've had to resort to shampoo on a couple of occasions. I'm trying to cut down the amount I wash my hair to every 3 days or so, but it's very hard cos I'm a right oily bugger!But yeah, why is it not working??? What am I doing wrong?
updated by @fay-brotherhood: 01/13/15 08:49:42PM

try and add a tbs or so of sea salt to your bs mix and maybe skip the acv; i did a little searching a few days ago because my hair was greasy after bs/acv too and it looks like since the acv is being used as a conditioner, it's not 100% needed other than to restore ph balance, and you can go with out it if the bs doesn't dry you out to bad, at least this is what i have come to understand.when i wash, i do 1/2-3/4 cup bs and 2 or 3 tbs to a gallon pitcher of water, or at least what's left after i put my hand in to break up the clumps, and it dries out my hair big time which is great because i can become a grease ball after a few days. i have noticed an increase in dandruff when not using the acv, but it's not really that bad and still an improvement over anything else i've ever used so i figure i will continue to do bs with sea salt for a few weeks and then once a month or so do the acv rinse just to keep things from getting to dried out

ahh brill thanks guys, I will try both of those. Its such a pain havin a greasy noggin :P x