^^^ What he said. I normally do this as part of the "put the bike down for the winter" maintenance, so I'm not in a rush to get the filter back on the bike. I clean and rinse thoroughly, then place the filter where it has good air flow all around over a drip pan and let it sit over night. If you need to accelerate drying and can't wait, you can use a low pressure stream of air (never use high pressure air) from a fan or hair dryer.
If this is your first time oiling a K&N, I think most of us tend to over oil them until we get the hang of it. Follow the directions, lightly apply oil to each pleat, let the filter sit for a short time and look for an even distribution of the red oil. Any spots you missed will be pretty obvious. If you go overboard, let the filter sit for a day or two to let the excess run either to the inner or outer end and then blot the excess with a paper towel or similar disposable product. Installing it with excessive oil will result in that excessive oil dripping into the cover or being sucked into the intake.
Jerry