Two parts of my day are the most frustrating. These are the bits when my 10 year old son has to do personal care tasks. Shower, teeth, ADHD tablets, inhaler, get dressed.
These tasks put together can take him between 15 mins to a hour. Its exhausting and so frustrating.
He gets distracted by so many things, constantly repeats words or sounds and gets off track in so many ways.
Any ideas ?
Well you've found what motivates him! 
He's going to be very wealthy in a couple of years.
Hi
Sounds like there is too many tasks within the sequence and too much variability so there's lots of points where decisions need to be made - the more choices and the more decisions, the more 'pondering' time gets created so the longer the sequence becomes.
I would suggest breaking the whole process into single tasks and you control / drive until you spot all of the 'pause' moments and figure out why it exists - and then engineer them out of the sequence. It could be little things like socks or pants first? How wet does a toothbrush need to be? etc. or things like playing with shower jets is too enjoyable and water flow experiments can be conducted while in the shower. The sounds may be a gentle stimming which can indicate comfort or discomfort - it's context related.
Think of it like building a car - the more things that the operator has to decide, the more errors creep in. Simplify the sequence and it becomes easier to perform perfectly - Poka.Yoke in Japan
