We have five 55 gallon tanks here and my least favorite part about water changes is the siphoning of the gravel, so I can totally feel where you're coming from. I wear sleevless shirts for water changes and keep towels handy so I don't "water" the floors when I take my arm out of the tank

With larger tanks, there's really not an easy way to get it done unless you get a tank big enough to do this
As long as you wash your hands and arms and rinse off any soap, it really won't hurt anything. Most of our fish are pretty friendly, so I get nibbled on.