That is great news that your chucks are endive crazy! That is a very healthy staple.

Hibiscus leaves are fine as long as they have not been sprayed with chemicals.

I wash my store bought greens, hang them to dry, then chop and store them the day before I feed them. I do not wash home grown flowers or plants. I don't think that you can completely avoid the moisture in greens. I try to reduce it a bit by letting the greens dry before I feed them, but I am not sure that wet greens are the issue with excessive fluid dumps in chucks. I think it might be more diet related, but I can't say for sure.

I use Repashy superveggie sprinkled on their food a few times per week and I sprinkle minerall calcium indoor a few times per week. I am not sure what you mean by mineral supplement. Is it a calcium plus trace minerals supplement?