Mine are in a run much of the time, but allowed into the garden a few hours each day. The garden is big and no smell there, but the run is a bit smelly sometimes. I have tried Type 1, builders sand, ordinary earth since they destroyed the grass that was there originally - they plough everything up. Now I have a routine which works reasonably well - at least in summer. I use lots of straw in their sheds and clean that out weekly onto the run, and the old straw is raked up, and wheelbarrowed to my compost heap. I must try stalosan. I have just used Diatom for everything previously.