Still fighting with red mites. Bit worried.

Hello again, i have been spraying the coop every 2-3 days, sprayed it few times now i can still see some mites, i have used diatom powder on the perches and the edges but they are still running about on perches, i just saw some now dont where they come from.  Chooks do go in at night but im worried how long will they have to suffer till what else can i do other than spraying poultry sheild.
I was thinking to block every corner and gap with wood filler and varnish it. Will it stop them?

Mo

keep using the poultry shield.The number of mite will get less and less.
 you can also try vasoline at the ends of the perches to stop them getting over to the hens

red mite is normally brought in from wild birds so try to prevent them getting in.

wild birds can land on top of your run so they could have come from there also if there are any trees close to your coop set up then they can simply crawl along. How are you disposing of your hens bedding when you clean them out? If you have redmites the shavings should ideally be burnt. When you clean the coops out do you do it in the run area? You really ought to clean the coop well away from the run to prevent the redmites simply crawling onto the ground and then climbing back up. If you cant move it then treat the surrounding ground.
Once a coop has redmites it can be a long hard slog to eradicate them and once they appear to have gone then keep on with the poultry shield treatment at least once a month to catch any that have hatched from hidden places or made their way back. Red mites can live on the ground for many months without feeding.