Yes, you will feel greasy if you have to wait 3-4 days for the BKT or other Keratin Treatments to settle in. You can find other alternatives such as Brazilian Blowout or Sun-Liss that get rinsed out immediately after ironing or after 1 hr. But think of it this way, it's only 3 days out of 3-5 months of frizz control and you may find with your texture of hair, that the products with 3-4 day waiting period may control your hair better than the quicker options. Your stylist should give you the best advice.
Search Treatwell for Ladies' Brazilian Blow Dry near you
During the initial 3 day period after the blow dry, you mustn't add any products to your hair at all, nor tie it back. I've got a similar hair texture and by day three, my hair is only just starting to look like it needs to be washed, which is fine, as that's the day you get to wash it! The treatment is really nourishing and combined with the natural oils in your hair, it sounds like it might help to combat your frizz long term. If you find that a normal salon blow dry lasts longer than a day, you'll probably be fine with this treatment, and think of the silky smooth hair that will follow!
To reduce the frizz try BEOX ACAI & GUARANA treatment. This product is design to reduce volume and frizz and adds shine to your hair. You leave it on for one day and than it is OK to wash it out. Try to get dry spray shampoo from BOOTS £2.49 it is great, just spray it on the roots and rub it in. Should get you thorough the day. And you have to get use to the feeling! Somethimes it is more in the mind!