Taken from another forum and the user who asked for help regarding cockroaches and bugs said it was brilliant.
Find a Bayer supplier or check with Yapi Market and get "K-Othrine SC 50" - less than 10tl and also buy a spray bottle to use exclusively with this - again around 10tl.
Dries on surfaces that you spray and stays effective for 3 months.
Also very good (not for them, but for you) for cockroaches and the like.
Behind furniture, under beds, in cupboards etc..
It does not stain, (so I was told) so painted surfaces are not marked and it dries into the paint.
Anywhere they might come into the house - door stops, drains.
Outside you can spray it on patio areas - again, where it is not going to wash away, but if you leave it a few days without washing most of them will have fed on it and be gone anyway