Digital BW, The Print

Purging HP DJ CP Print Heads

Here's a good question that I'd really like answered by someone who 
has actually successfully "done the deed".

How do you purge and completely flush out an HP DesignJet 2xxx/3xxx 
CP Printhead?

Anyone have any idea where and how to buy just the HP DJ CP Print 
Heads?

Any suggestions as to any Websites where this topic might be 
discussed?

This becomes a real issue if you start using the fancier 3rd party 
vendor replacemnt inks and dyes that aren't compatible and 
intermixable with the HP OEM inks dyes.

The reason for posting to non HP Designjet E-Groups is that several 
other large format printer manufacturers use the HP DJ CP Printhead 
system. Feedback is welcome from any quarter..

All the best!

TG