Beeboy, I just cut out the bottom under the hive and staple the screen in, add a compartment under it 2 sides and a front with a hinged door at the back and a bottom. I build my pan to fit, and used to use oil, it does work, but I changed to water with dish washing liquid in it. it works too is easier to clean. during the summer I do have to keep a watch on the level, with the heat you can get some evaporation so you may have to add a little water.
Good luck to you and your bees,