Vegetable oil for the chicken coop?

I dont know if Iv done a good thing or a bad thing. But my chickens ended up with leg mites after we took in another persons flock and for some godforsaken reason I didn't quarantine. This led to a whole host of problems cause those girls were NOT in good shape. But this isnt about mites, mostly. Anyways so we treated them with vegetable oil  and it got all over the outside of the unfinished coop. The coop is built out of free pallet wood and I never got around to applying a finish or painting it. I decided on a whim to take the oil leftover from treating the girls and paint it onto the wood since we wernt going to get the splatters out anyways.

Is vegetable oil painted onto my coop going to cause any issues to it? will it attract flies or will it dry out before winters over? I know it wont cure but I know some people use it on the inside of there coop for mite control and it looks really pretty compared to before. I figured if its going to cause a problem Il just take the propane torch to it and char it like the first coop. (in a controlled manner, Yes I know oil is flammable.) But if its not going to cause any issues id rather leave it and be glad I found a use for old fry oil.  

Oil is usually used to preserve wood.  Oversimplified to the extreem, it replaces moisture in the wood and strengthens it.

Usually it's a "drying oil" like linseed (flax).  But, i find any oil made from fresh vegetable matter will harden (cure) over time.

A lot of old books recommended treating the roosts,nesting boxes and floor with oil several times a year for pest control and long life of the wood.  

My concern is you mentioning old fry oil. While I am not a fan of what they do to make vegetable oil... it doesn't go rancid. After you fry with it though... I worry it might go rancid and smell bad. On the other hand, if its a thin coat... in a chicken coop, it might not be noticeable.

Figured Id give a update! The oil has completely dried out in just a week. It was a pretty thin coat and we've had 45 mph winds this week with temps between -12f and 45f. It has left a pretty color to the wood and if I ever remember to take the phone out with me Il snap a pic to put up. Hopefully it will continue to do well and I will update this summer when its 100f! Then we will see if the fry oil finish attracts flies, My real true worry.  

Would nt your chickens eat the flies?