My personal observations with this type of behavior tell me three things: it's not specific to giftedness (though the gifted proclivity to perfectionism makes it more likely), it's not something one necessarily grows out of, and it can become a limiting factor in future success. I'm most easily able to observe this behavior in the technology field, where you find people who are unable to successfully diagnose hardware/software problems, because they are so afraid of breaking things further that they require significant handholding and never take a single step forward in the troubleshooting process on their own. They find themselves sidelined, and do not advance in their careers.
So, I would recommend taking this seriously as a potential problem, and addressing it at an early age.
Apart from the many strategies for addressing perfectionism in general, for this specific problem I'd add one: give him a time limit, and once he exceeds it, choose for him... and if you know he has a preference, choose the one he'd like least. So if you know he likes baths over showers, choose shower. When he immediately protests, tell him it's too late, and let him experience the consequences of failing to choose in a timely manner.
If you're not certain of a preference, then choose the one that's more convenient for you.
