I went the tub of water route at first, but I found I was always so nervous about the temperature being "just right" that it sort of spoiled the fun of the process. (I never liked fighting the off-temperature crossover effects.) So, I engineered a simple and cheap tempered water bath out of stuff you can get easily on eb*y and local stores. Here's a link to a post I made on APUG that describes this: http://www.apug.org/forums/forum40/1...velopment.html
While some will say this is overkill, I feel it really helps me relax and enjoy the process, not worrying about temperatures. Also, it gives me enough space so I can do processes like dip and dunk with lights out, not having to worry about monitoring temperatures.
That said, the tub of hot water did work fine for me until I built this. Color processing is sensitive to temperature, but it ain't brain surgery. Go for it!