[ForSale-Swap] How to clean a printer head???

[Jim Isbell]

I have several various ink jet printers that I have retired over the 
years.  Most were retired when the print head got plugged from disuse. 
 I have an old HP Laser Jet that I use for B&W and the color printers 
(because of the cost of ink) sit a lot.  

Is there a way to clean a printer head when it gets beyond the point of 
the built in "cleaning" process or in the alternative, is there a way to 
keep the printers sitting around without gumming up?

I have several old Epson and Cannon inkjets that I would like to 
resurrect but Ill be damned if I will pay more than the price of a new 
printer just for a NEW print head.