The general advice is to just keep going until you have succeeded in doing 9 to 12 flushes in all. The principle of following the protocol is more important than counting stones. I like to see the live-flush as part of a lifestyle change; you have to make improvements to your diet and way of living, which assists in cleansing the organs. Your diet needs to be such that you are not compromising the function of the gut and in particular that you drink sufficient fluid every day. Poor hydration puts the electrolytes out of balance.
More specifically you could consider increasing the Epsom Salts . You can double the quantity.
Any type of grapefruit is good enough for the liver-flush. It doesn't have to be pink.