I personally would use a syringe or pipette, but then again, I work in a lab.
So I would suggest making your own funnel. You can make it out of tin foil. Cut a disk out, say around 6 inches or so. Fold in half, and then in half again. You'll find that you can open it up into a "funnel". You may want to tape the seam, just in case to prevent leakage. Then cut the very tip off with a scissors, and presto! [/macgyver]
Hope that helps!