It is good stuff. Put the rifle on a bipod with the butt supported or otherise manage to angle the muzzle slightly down. Insert the straw into the chamber firmly to prevent back-leakage and give a couple seconds squirt. Watch to see if it comes out the muzzle. If you see fumes coming out the muzzle, which you can in good light, you are really close. Give very short squirts until it reaches the muzzle.

With a wood stock, I would put a small square of cloth into the chamber draped like an apron out over the stock by the ejection port to guarantee you don't get any on the stock as you remove the tube.

BC, do you inject it through the back of the bore guide? I never tried that. I guess there is no reason for it not to work, it just uses a drop more...