Just completed a test using the oil drawers versus dry drawers and home mixed hive clean costing £ 1.55p, done on two colonies side by side, swaping new drawers between at regular hourly intervals and counting as you go.
Overall showed around 180 dead adults trapped in the oil all dead.
The floors without oil revealed only a dozen or so and some still alive and the rest presumably still alive somewhere back in the hive.
It is clear to me that a simple coating of cooking oil on the drawer out performs all the commercial sticky boards.
Same technique for moquito control simply coat the ponds in which the larva live and breath with a quick coating of oil.
The home mix hive treatment performs just as well, save your monies and make your own.
The simplest of things have all been done before.
Edit.
There are other similar products on the market that can be altered to perform much better by simply making a framework around the correx sheeting to contain an oil bath rather than just a thin film so he mites cannot walk away.