Adding water to chocolate is going to make it seize, and then it is useless.
You may just have to try different chocolates to test viscosity, they are all different. I personally don't want my chocolate thick for dipping. I prefer a more fluid chocolate so the dipped items look better.
I have been in a class where a small amount of water was added to the chocolate, it was stirred vigerously (immediately from when the chcolate was added) and it did not seize. It does thicken the chocolate but I think if you did that the chocolate would be too thick to work with for dipping. I asked for a scientific explanation of why the chocolate did not seize but didn't really get an adequate explanation.
The chcolate is not useless after it has seized. It can be used for ganaches. It just cannot be used for tempering even if remelted.
You might try double dipping the chocolates for a thicker coating or as Robyn suggested look for a chocolate with a thicker viscosity when tempered that would give a thicker coating. www.chocosphere.com has product information, at least on some brands, about differing viscosities of the various chocolates.
Look for a lower % cocoa butter chocolate, ask for it from your supplier, or if looking for higher quality, a similar % cocoa butter in what you're using now but without the emulsifier such as lecithin. Look at the viscosity given for your paste and request a higher one.
Water brings on problems with how the chocolate melts down in the mouth and texture when eaten. Water can absorb up to twice its weight in the sugars, making a syrup, and the sugars can crystalize to larger and larger sizes over time making it gritty.