Ice cubes

The ice cubes part : if your bathroom is very warm, the water warms up pretty fast, since some of your own heat is transferred to it too. When your BD lasts over a few minutes you will find that the water is not cool anymore.
And :
I don't like getting up and changing the water in the middle of the procedure.
This is why :

Unlike some other types of sitz baths, this is NOT ONLY about moving the lymph. A very important effect of the BD is the stimulation of parasympathetic nerve impulses. If you just spread your cold water fretting because it takes too long, if you are stressed in any way, because you are cold, you are in an uncomfortable position etc..., you are missing half of the point. This is why it is not a good idea to read, listen to the news bulletin etc... while doing it. You should just concentrate on what you are doing and on the feelings experienced all over your body.
When your sympathetic effect is activated, you will feel very relaxed, sometimes you hear a humming sound in your ears, you start seeing slightly better, it is a pleasant experience. In fact, you could have gone on longer that prescribed.

In fact when you have finished you are very relaxed. You have just given to your body a few minutes when stress has been deactivated. I found that by doing this regularly I can recall more easily during the day in other activities that slight internal tremor that signals the spread of the anti-stress response. Maybe this is also a retraining of the nervous system? Maybe BD can help you reverse the stress training we are subject to at work? I suspect so.
Today for me is only day 38 I think. I shall report later if you are interested :-D