You will not get an accurate blood test within a period of time following a liver-flush. The exact time to wait is dependant upon one's own metabolism but 4 weeks is recommended as the minimum time. A liver-flush usually has the effect to deplete the potassium balance temporarily and some people consume a potassium broth after the afterwards. Dr Richard Schulze has a potassium broth recipe.
If you have been taking supplements long term to dissolve stones these can also change the potassium level. Many supplements as well as healing our livers are diuretic leading to the loss of potassium.