Chicken with scaly leg

One of the chickens has bumps on her leg which look like scaly leg - which is caused by a mite that burrows under the leg scaled. We couldn't find the chicken mite treatment (or the slug pellets - maybe they are off together somewhere with the pen lids and odd socks) so I put some cat frontline on her. According to the internet this should be effective although not licensed for chickens. It takes some time for the lumps on the legs to go away apparently so it is hard to tell whether it has worked. We may also treat her with the other stuff when we find it - and should do the others too. It is very tricky groping around by torch light. We thought the hand reared ones would be friendly - but they are not.