Your tongue is telling you what you already know - there be critters there. ;) As long as you're bowel cleansing, stirrting things up and getting things out of there, you can expect to see cracks on your tongue. They'll go away when things equalize. IF you're not doing any cleansing and the cracks return, then it means you NEED to do cleansing and get rid of whatever is upsetting your body. So you're on the right track for now, just keep it up! :)
I'd lay off the lemonade for awhile, your body is plenty stressed by all the cleansing you're doing. Plain water is great, as is Bentonite clay.
1/2 a lemon is okay when mixed with apple cider vinegar to increase gastric juices/power of digestion.