Blow or Suck - Which is Best?

In my years as a consulting software developer, I had the opportunity to work with a small firm Unit Design. They manufacture small scale circuit board production equipment, to include defluxing cleaners. These cleaners were built of standard home dishwashers, with added and removed components to support the new application. The cleaning solvents were typical surfactants mixed with deionized water. The customers for this kind of equipment were most commonly those which build small batches of military hardware; one-off kinds of builds. If I get the spelling correct, one kind of cleaner used was *keizen* though as I recall it was a bit volatile and so difficult to use. Generally however, we were quite able to use more common household or industrial surfactants to clean circuit boards without damage. For the purposes of list readers, I expect that a dish washer will work fine. The one question I have (caveat) concerns proximity of cleaned boards to the heating element in the sump. We did not have problems even with seven, eight, and nine layer boards but, the boards of PDP and similarly aged boards may be more delicate. What say any readers who actually use a dish washer for cleaning of older boards? William R. Buckley