Back a few years ago we talked about using things like dollar general dry cloth refills for the Swiffer sweeper, and Clorox brand handi wipes multi-use reusable cloths. It works good for some and not much for others. I think I first read about this on the Aussie forum. You will get a few bees caught in it also.
For your oil tray I started using a cheap dish washing liquid in water in my trays instead of oil. In the summer every now and then you have to add more water because of evaporation. Soapy water kills bugs just like oil, it doesn't smell as bad when you have bugs in it and is a lot easier to clean and refill.
If I had enough SHB's to catch 50 on a cloth I would have reinstalled the DVD cases with a teaspoon of Crisco in the center and a ring of Fipronil around it. Take a heated ice pick to make a coupe of extra holes in the side, leave top and bottom solid. Don't make the holes big enough for bees to get in. I have put them on top of the inner cover, and once in a while on the top frames. If you have them bad, You can put the just inside the hive at the bottom.
Good luck to you and your bees
Joe D