There are a ton of them.

Horsetail, couch grass (also called dog grass), corn silk, goldenrod, clubmoss, and cleavers.

I'm still not certain if these type of cleanses are a good idea. I would be careful with them if your kidneys are weak. Corn silk by itself is something you might want to consider, as it is demulcent and seems to be a little gentler.

All I'm taking for the kidneys at the moment is chanca piedra, renafood, and cranberry juice. And drinking plenty of water.

http://return.to/organicherbs has both.