Rdanell,
For break in to work you need not play through the speakers, the signal entering the phono stage and being processed is all that's required. If you have a stand alone (outboard) phono stage there could be some advantage to resistive load at the RCA outs.
Some equipment is vastly improved in 100 hours, some require several hundred hours. This is not a new concept, lots of Audiogon members have posted their experience.
You can put a record that skips and never goes further for 100 hours:-)
Marakanetz, actually that would work but I'm not sure the cartridge would be the same afterward :^).