I may be in the minority but I have never taken my pumps apart to clean them. I recirculate boiling wort the last 10 minutes of a boil for the post boil or cold side pumping I will do after the wort has chilled. I use an immersion chiller and recirculate wort to speed up the cooling.
For cleaning I fill my BK with hot water routing the water back through the pump is reverse. I dump in some oxyclean, brush it around then recirculate the oxyclean solution through my BK pump and hoses for 5 min or so, then pump the BK dry. I then use the same reverse flow method to flush cold water through the pumps and hoses for a rinse.
I refill my 20 HLT after transferring strike water to the MLT. After the mash I use the HLT pump to pump the water I use to fly sparge through my HERMs coil to flush it as well as the remaining 8 or 9 gals of hot water. My HLT pump has never pumped anything but water since I bought it.