Hello
For that flies we use here "Yellow boards ".
This are little yellow cardboards with a speciall glue.
There is no other chemistry.
Put them in the near of your Cham-home.
The flys like that yellow colour , and the glue catch them.
you can buy them for a litle money in every Gardencenter
(at least in germany , but i think ,you can find it in your country also ).
Regards nobby