I have been using Carlson's Lemon Flavor for about three months now and
love it. The first bottle I bought was the 16 oz one. It lasted about 2
1/2 months at one teaspoon a day. After the first month and a half I
started to notice the taste was not as fresh but I finished it anyway.
When I reordered I got the smaller 8.4 oz bottle. This one lasted about
35 days and the taste was as fresh at the end as at the beginning. You
pay a dollar or so extra for the smaller bottle but I feel it is worth
it.

I tried several other brands but could never stand the aftertaste. Often
a day or two later I would still  be getting a rancid taste and burps.
With Carlson's I do get a little aftertaste that is left in my mouth
(but never in my stomach) but I have discovered a way to get around it.
I take the smallest taste of plain yogurt. (I know it is non paleo). I
buy a large container of yogurt and use ice cube trays to divide it up
into ice cube size servings. I freeze the yogurt for long term storage.
I take one cube at a time and let it thaw out in the refirg. Then I take
a very small amount before and after my teaspoon of oil. One yogurt cube
last about a week, thats how small of a taste of yogurt I take, just
enough to coat my mouth from the oil. Frozen yogurt separates after it
thaws but all you have to do is stir it a little before use.

Tom