I put on nitrile gloves and pack 'em by hand. That way I can see they are getting fully packed. Never tried the sandwich bag method but I'd be afraid of trapped air between bearings. By hand you can rotate as it fills and watch them fill.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.