The slow cooker/crock pot works great! I bought this one at walmart when it was on sale for $18. works like a charm. the cheaper models have the nob like this one that goes from a keep warm up to 450 degrees. somewhere half way in the keep warm range it will hold the water in the tub at 100. i usually do it in the bathroom and put warm water in it to begin with. I use 30 ounce brown glass bottles to keep them chems in as they star warmer that way. I turn on the cooker and them fill the bottles with the chems and then put them in the cooker for about 30-45 minutes to come to temp. I have one filled with water and have a thermometer in it to measure the temp. I can then fine tune it (kind of) by adjusting the temps. it works great. I got the idea from a link in a post from here. I have it saved at home but im at work so i dont have it with me. will try to post it later. here is a link to the cooker i bought. Get the cheapest one you can find and make sure never to cook withit