Help with zirk fittings

Years ago I bought a 5th wheel with grease able hubs. I fallowed the manufactory recommendation, jacking tire off the ground and slowly turning tire as I greased the hub. Took about a half a tube per hub. The following year I pulled the drums off to check brakes and found 3 of 4 brake shoes had grease on them. I called Dexter axle at the timed spoked to a tech, who said the the grease able hubs have been around a long time. They were designed for boat trailer, to push water out of hubs. The RV industry had jumped on the band wagon as a selling point. His recommendation was to inspect once a year for possible grease by-passing seal. You can take your chance on brake shoe contamination and not stopping when you need them or do it the right way and hand pack bearings. My trailer brakes are to important to me to take the easy way out and just pump grease into the hub and hope the seal won't leak.