function>maintenance>station>Nozzle Wash
is my go-to for head cleaning. you can set the timer to a max of 99min but i've also run it and turned off the printer (switch off in back to negate sleep-mode cleaning cycles) for an entire weekend to let it soak REAL GOOD.
Custody Wash does the same thing, but when the timer runs out the carriage slides out for access, and if you're not around... the heads are sitting in open air, drying out, because you forgot about it.
Nozzle wash stays parked after process is completed, so I just stick to using it fulltime so I'm able to walk away and forget about it.
Head Wash, however, has you pull your ink supply and then it empties out the lines, shakes itself vigorously to knock loose any ink in the dampers, and then asks you to insert the cleaning cartridges and it fills/empties/shakes out cleaning solution through your lines/heads
(might not hurt to have these around, you need 8 but can get away with 4 if you know how to do this process 2heads at a time instead of all 4)
(*note Triangle inks have 440ml cleaning cartridges for the same price as Mimaki's 220ml's... there's no difference, just get 4 of the bigger ones and you'll save $200+)
Also noted... Head Wash is useless if you've got clogged heads/lines. You'll just end up burning out your pump if you try to do this with your current issues.