Dusk can kill electronics by localized heat buildup.
The Apple iMac is a terrible design in this sense: it is difficult (just not feasible for most all users) to get at the internals to clean off dust, virtually guaranteeing an abrupt failure, typically of the video card. Worse, the tight iMac internals leave little room for error on cooling.
Not so with the Mac Pro, which really does have a 'genius' design for cooling. Even better, dust is easily removed, as shown below.
I use a combination of canned air and a powerful nozzle on a 1300 watt HEPA vacuum cleaner. Never make actual contact with the electronics. I maintain a 1/2" or so distance using a inch nozzle of about an inch in diameter (no brush!). That creates a suction powerful enough to suck off most dust, even the stringy stuff.
The vacuum cleaner not only can suck off most of the dust, but placed on top of the Mac Pro it can spin the Mac Pro fan to very high speeds sufficient to make it whine from the RPM, all the while spitting out clouds and clots of dust. This works for other fans in other computers also. It easily removes dust that dust off usually cannot dislodge. The dust off is mainly useful for nooks and crannies (keep the vaccuum cleaner running with the nozzle nearby to avoid contaminating your work environment).
I had not cleaned my 2013 Mac Pro for nearly a year. As seen below, significant buildup of dust can occur internal to a machine. The localized buildup of heat can be substantial when dust accumulates like this (a system failure can result from one tiny component). The image below is a mild example compared to what I used to see in my 2010 Mac Pro.
We use the EasyGo CompuCleaner - Electric Computer Blower for Electronic Devices – Alternative to Compressed Air or Canned Air with fantastic success! Just clean out the filter on the bottom after use, which take no more then 60 seconds.
Generally agree with you. I do this every year as IT manager where I work. Yesterday, my son and I blew out 30+ Mac Pro’s (2008 to 2013) models. Wearing face masks and googles. It was a dust storm!
One point of difference…. I read somewhere in the past not to blow fans to very fast rotation while cleaning as the bearings and fan design are not built for that rotation speed. Especially opposite direction to their normal turning. So while we blow them we are careful to not turn them like a jet engine.
MPG: Interesting option that looks very worthwhile in some cases. One issue is raising dust best not raised (outside the Mac), but with a vaccuum also running sucking in the dust it might work well to keep the dust down (I also have a large HEPA air filter I can run nearby).
Fans: forcing the fan to spin at extreme RPM for very long is not a good idea. Also, a vaccuum cleaner used as described spins the fans in the natural direction; a blower forces the fan the wrong direction. So don’t use a blower to spin the fans backward. Finally, the 2013 Mac Pro fan is presumably high-spec with good bearings, and not easily damaged.