If you were using oil in beetle barns there is no wonder you spilled oil. I think you probably meant Beetle Jail Jrs.
I've had great luck with the Beetle Jail Jrs. They do what they're designed to do...they catch beetles. You do have to be careful and not tilt them over enough to spill oil out of them, but with any oil trap in the upper levels of a hive you have to be careful. Also, don't fill them over 1/2 full. I spilled oil once from one of them, thankfully there was no noticeable harm done and the amount was small. It alarmed me enough that now I am extra careful when working with them (as I should have been to begin with). Bottom oil trays work well, also, but if beetles manage to get past the oil trays (and they will) it is good to have a few traps scattered within the upper levels of the hive.
I'm in south central Alabama and just getting started. I figure I might as well go ahead and get my mindset geared toward perpetual war with SHB...they're not going to give up. Thus I'm working and studying every angle I can find to limit SHB access to my hives and to kill those that do enter (or get close). I've got some beetle barns that I haven't used yet...I'm toying with non-toxic ideas for them.
I'm a satisfied Beetle Jail Jr user, just ordered a couple more dozen for future increases in my small yard.