I'm a big fan of not fouling my bore prior to a hunt. Many times I will keep my gun loaded for extended periods of time and do not want to have to clean my gun after every hunt. Basically, once you foul that bore with powder your going to need to clean it pretty soon thereafter. Remember the old adage, "never let the sun go down on a dirty bore".
We all have developed our own ways of doing things over the years but here's mine. Prior to loading up for a hunt, I will pull my barrel and give it a good flush and cleaning. At this point, I do not add any oil to the bore. I will however pop a couple of caps to make sure all is clear. I can tell by the report of the cap whether my path is clear. To me, if there are no obstructions, the sound of the cap being fired will pretty loud. Some like to point the barrel toward some grass to see if it moves. I have never done this but it sounds like a good idea to me.
By doing this, I have never had a delayed fire or a misfire. Again, this is my ritual and may not reflect what others do. Also, I can keep my gun loaded this way for a long time without any damage or corrosion to my bore.
Jeff