Something else to remember when using oil trays...you don't have to fill them up. Just enough oil to cover the bottom is all that is needed. You need to figure that the tray will not be laying perfectly flat (unless you have your hive built by NASA

) so add a little extra to the shallow amount. I use baking pans which have sides maybe 3/4" tall and I fill them at the *very* most only halfway full, most of the time only about 1/4 full.
Lots of people use vegetable oil but I prefer mineral oil as it's not attractive to insects and other critters. A pint for $2 is the best deal I've found so far, which isn't cheap...but I can load roughly two trays with a pint and that will last most of the season. Again, don't overfill them...all the beetle has to do is hit the oil and he's a goner...he doesn't have to sink below the surface or anything. As debris falls into the tray a level of capping wax, "bee dander", bugs of different sorts, etc., will build up in the oil and it will need to be either replaced or filtered through an old flour sifter, a piece of window screen, or something.
PAM is definitely good to use being as it won't spill out, but it might have the "critter attractant" aspect to it.
This reminds me that I need to check with my local pharmacist and see what the cheapest they can get me a gallon of mineral oil for...
I tried the "Handi-wipes" last year. I actually grabbed their counterfeits at a "Dollar Tree". I "fuzzed" them up good and laid them on top of the inner cover, my escape holes and feeding holes are screened so the area between inner and outer covers are bee-free. I still have two hives with the wipes on them...the bees have nicely glued them down to cover the screened escape/feed holes. When I first put them on I failed to see any trapped beetles. Since the bees have sealed the holes beetles are seldom (never) on top of the inner cover so there's no chance for them to get caught in the wipes now. If I decide to tear off the sealed up screens and replace them with fresh screen I will stick the wipes back under there and see if they catch any beetles. Apparently the wipes work for some people, but didn't do much for me.
I think the best traps are in-hive traps, such as the in-between-frame traps (I use Beetle-Jail,Jr's but there are others), entrance traps, and screened bottom boards with oil trays. Just be careful handling the in-hive traps so that you don't spill any oil in the hive...oil will kill bees, too.
Best wishes, keep those oil traps full!!!!
Ed