7 1/4 axle bearings are one piece sealed bearings. There is no way to pack them. Use a tire as a slide hammer? Good way to booger up the threads. Why not use a slide hammer as a slide hammer? You'll need one to pull the seal anyway.....
7 1/4 bearing is a sealed unit, like a big skateboard bearing? Wow, its been a while since I blew up my 7 1/4! Slide hammers are great if you got one, with the axle adapter. If you didnt bring yours to pick-a-part, you find ways to get stuff out with what you got. Threads are tough, doubt if they would even feel one grate, thats all it takes. Your right, it takes a special tool for a special procedure to be done properly.