Cooling system flush on 1996 Honda Odyssey

What is the best way to drain the coolant from the block? A Honda technician advised to not remove block drain plug located on engine block rear side near oil filter. Is there more than one drain plug? Supposedly the threads in the block can become damaged cosequently rendering the engine unusable and not repairable. Is there any other way to drain the block such as a frost plug that is user friendly?

Asked by for the 1996 Honda Odyssey
why do you want to drain the coolant from the block? you can pay someone to flush the system and it will accomplish the same thing. no one and i really do mean
no one tries to drain coolant from the block.