We recommend coir coir for use with our composting toilets as it is a by-product of coir rope manufacture and is a sustainable alternative to peat. Plus, they're easy to store, transport, and last forever.
They are not only available from us or via Amazon, but also in garden centers and in many other countries in Europe and elsewhere , where people buy plants and accessories. The designations are different, e.g. humus bricks, coconut soil , etc., as are the packaging sizes. It is only important to ensure that the coconut fibers are unfertilized and left in their natural state.
Alternatives? Composting toilets work odor-free if the contents of the solids container always remain dry. To ensure this, you need an absorbent substrate that absorbs the moisture from the faeces, but also releases it again so that the fan can transport it away.
Substances such as cat litter etc. would absorb the moisture, but then clump together, with the result that the toilet would not work or would only work for a short time.
Sawdust, bark mulch, litter for small animals, leaves, hay, straw, etc. do not absorb enough moisture and are therefore just as unsuitable. These substrates are only suitable for sprinkling on conventional dry composting toilets, since there it is more about privacy than drying.
If you run out of coconut fiber while travelling, you can fall back on peat or, if necessary, very fine sawdust.