What Hector says has some truths to it, but as his fitting is in, or near the middle, you need to pump enough grease into the hub so that it fills it and moves both direction filling the bearings/cavity. The bearing buddy holds the same principle, as it pushes greases through the middle of the hub toward the rear, so you again need enough grease to fill the hub and reach your bearings. Once the hubs are filled with grease, using either method, you will only require several pumps to maintain your wheels. So, if you're greasing to the middle through the top of the hub, or through the middle of the such as the buddy, you still need enough grease to push it to both bearing sets. As Hector says, doing something is better than anything. For me, just my opinion, but growing up in Key West and working a number of years in the marine industry I found the bearing buddies to work great!! I used them on both my boat trailers and my snowmobile trailer when I lived up north. Those who didn't have them went through hubs and bearings like crazy
Regards,