DS isn't old enough to argue yet, but I do have a habitual arguer in my house...my husband!

For context, he has a traumatic brain injury and his disability causes him to be very anxious about doing certain physical tasks like standing, walking, and sitting back down. Each night I help him use the bathroom and take a shower. During this routine i give him a lot of directions and correct anything that I think he's doing "wrong".

Those of you with older kids, how would you deal with constant arguing while you're trying to help your child and teach a skill? This has been going on for a couple of years now, just about every night and it drives me nuts! I feel like I should give him some space to do some things the "wrong" way, but then I worry about safety. Thoughts?