I have read a lot on the subject though and most say that if you are working with very hot (not scalding!) water and very cold water then you keep the feet in as long as is not uncomfortable, which is probably less than two minutes, and then switch. Try to keep it about the same amount of time. Basically, by going with your feelings you are ending when very hot, ending when very cold, however long it takes to get there depending on water temperature. There really can' be an objective 'soak two minutes' because whoever says that doesn't know how hot or cold the water is.
In some people with high pain thresholds you may need to set an objective limit just to be safe (avoid burns and frostbite), and experiment at first to make sure you are not damaging yourself. If the cold bath is mostly water it should be okay for a short soak. Generally with hot water we are less likely to burn ourselves because we can't stand the heat long enough. Make sure you test the hot water with a lukewarm foot, not a frosty foot. The water can be nearly painfully hot, but not exactly painfully hot.
About starting and ending, the majority of sources say you should start and end with heat or cold based on what you have found to be the most effective alone. For me in my flaring pf stage, that was cold. Some people don't respond to icing, as the board indicates, and prefer warmth.
Another criterion for deciding is: if you are about to embark on any physical activity, you might go with warmth at the end. IF you are doing this after physicial activity you might go with cold.
Many people find contrast baths very effective. They really wake up the energy in the feet, so try focusing for a few minutes afterward on recieving and being aware of the sensations happening in the feet, one of which may be a subtle tingling.