I understand the importance of cleaning and/or replacing the oil pump, oil cooler, etc. when rebuilding a motor with a spun rod bearing, but the fact is almost all spun rod bearings are due to incorrect clearance, heat expansion, or oil starvation; not a piece of debris in the oil getting in between the clearance area
. Flame suit on, but it's just a fact.
I've taken apart a many a spun rod bearing motor, ones that were ran a good while after the initial failure. The other surviving bearings did have scuff marks from the debris in the oil, but none ever spun due to the debris.