I have always hand packed. I would wipe all the old grease off down to spotless metal. The bearings would get a wash in camping stove/lamp fuel and then a rinse. Then once all was spotless I’d repack with new seals. My new TT has the new zerk fittings. I haven’t repacked yet since it’s only been out about 8 times maybe 1000 miles total. I may just clean and hand pack for peace of mind. I’d love to hear some more opinions here since I have the same inquire. I wonder how bearings look after 10 years of zerk pumping and how clean and un pitted they are vs cleaning and hand packing?