The Dexter axles with the grease nipples are called EZLube and the difference between them and bearing buddies is that BBs keep the grease under pressure which puts extra stress on the seal and helps dump the grease if they leak. OTOH, the pressure helps keep water out of the boat trailer bearings if they are dunked.
In either case, you should use the special seals that are made with two (not one) seal lips and an integral spring. Unfortunately, I have not been able to find them except from Dexter and Scamp
(haven't tried Casita). The regular parts places cross-ref the Dexter number (in my case 10-60 for the 1 1/16" axle) and give me a seal that either only has one lip or the second lip doesn't stand as high as the first (IOW, they are not parallel).
Pete and Rats