Water Pump/engine Flushing Question

OK the owners manual for my 2005 LF225TXR says to use the flushing connection to flush my engine for 15 minutes while it is NOT running. My question is this: Does the water pump in the lower unit need flushing ? (I would think it is a good idea). If it does do I just hook up a set of flushing ears while the engine is being flushed through the connection on the engine and just let the water run WITHOUT running the engine ? This website is the best and most helpful I have ever seen. Thanks to everyone who shares and the great techs that help us all out. Have a great day and thank you in advance.

[Tucker]

Yup, I've been bailed out more that once by the guys on here. This is a collection of guys that have lived through most of the problems you'll ever have. I remember reading here about a guy that used the flushing attachment religiously but had a considerable amount of salt build-up and corrosion behind the thermostats. I run the engine when using the flushing attachment in addition to hooking up the earmuffs. Initially a PIA with 2-hoses then I just rigged a Y-connector and made a short 6' hose. Someone should chime in with just where the water goes when using the flushing attachment. Sounds like it doesn't get into all the water jackets. It may have to do with the thermostat not opening right away.