I do the final rinse and clean of paint brushes and rollers in the big sink. Also used to wash our dog in the sink before she had to be put down a few years ago. The memory of her skinny shivering body and big pleading eyes still comes back to me occasionally as I'm counting down the fixer.
Wine making: Good idea and if your wine ever goes bad on you (vinegar) you have a large quantity of stop bath. Just a thought but there is a very fine line between the two. Left some of my wine ferment too long and had 5 gallons to dump.