Yes but dish soap by its design is a very searching liquid allowing it to creep into areas that are not easy to see, while the anodising of the block and the steel used on the reg offers good protection from exposure from water, long term exposure to the chemicals and salts can cause corrosion, particularly the small screw holding the valve in place, if that gets corroded, it will most likely ruin the thread in the block requiring a repair. (I have had to fix several blocks due to this)
While I have used soap in the past, a can of spray leak detection spray is a better option, even then I have had to resort to complete immersion in water to find partially stubborn to find leaks.
Regardless of what you use, carefully drying and light lubrication will hopefully stop any issues before they start.
Bb