For me, a 5 shot group is always my minimum.
Have you chronographed your rounds? If you have a high ES/SD, you will typically have larger groups (ie flyers).
I put about 100 pieces or so into a 1 gallon ziplock bag and then spray liberally with a home brew of lanolin and alcohol. Seal the bag and roll the pieces around for a bit. dump into a pan or just leave the bag open for a few minutes for the alcohol to flash off. Works better and is cheaper...
If it's from a vehicle, the Vortex Pro is a good bet. For backpacking, i like the Slik CF 634 (use the code "randy" on gohunt.com for a discount if you go that route)
I would think you should be able to find some scent and put it on a bumper and then pull it around, leaving a scent trail. Similar to how they train dogs for pheasants.
LoL
I've spent a few nights out since this post, and I was surprised how well I actually slept (except for one cold, wet, windy night). I did take extra precautions. Such as making sure I ate dinner and had my food bag back up in the tree before dark (I did keep glassing until complete...