Loose Coco Coir by GROW!T
If you're going to have a composting toilet, you'll need cover matter. Lots of things work; some we've tried (sawdust, wood shavings, coco coir), some we haven't (leaf mulch, etc.)
We bought bricks of coco coir and did the whole hydrating thing—and didn't like it. (That said, buying bricks and hydrating is cheaper.) Then we found this bagged coir, and we love it. It's a little pricey but mixed with free sawdust and cheap shavings, it works great.