Suitable powder disinfectant is hard to come by, i only ever see it at one of the shows we go to and stock up there. Its lemon smelling, yellow and comes in silver bags approx 1kg and a little goes a long way, haven't got any at the mo and i'm danged if i can remember the name of it. Can't locate it on web either. The most usual brand is Stalosan which i think is disgusting or Lysan which is primarily used for chickens.
I do use Vikron or Jeyes solution in the concrete buildings and only the powder in our wood floored huts.
When i get some more i'll let you know.
Mandy