Re: Only half the story
My 2006-era dishwasher has had 2 faults in it's 15 years of frequent use.
Both in the last 18 months.
Both can be described as gunk accumulation.
One was gunk on the door seal that lead to the catch tray filling with water and tripping the float switch.
The other was gunk in the drying vent's drain that eventually stopped the flap from opening. That required a fairly extensive disassembly to access but then just needed a good clean (inside various components).
Parts cost: zero.
Earache from the Mrs, however: "well why don't you strip it down and clean it out every year so it doesn't build up"... Well, if it took 14 years to cause a problem and is now completely clean, I won't need to do it again for 14 years and even then it's a fairly easy job. No, I don't think doing it annually is worthwhile.