do you know whether changing the location would affect him? you might setup a recycling system and find that since its not the same location it doesn't have th

do you know whether changing the location would affect him? you might setup a recycling system and find that since its not the same location it doesn't have the same effect. Part of the fascination could be the snug feeling of sitting in the bath or not having to wear clothing, it could be the temperature in the room, the colours, the light level, the tiles or rugs, the smell or perhaps the mirror or the windows or the room could be a safe place for him such as memories of being bathed when younger and the water is part of that self-soothing mechanism. You might try setting up a similar experience to the bathroom in his bedroom or another safe space as an alternative option, a bath like container with blankets (or without if he prefers to not wear clothes) you could then introduce a water flowing system or fountain and see if it has the same effect. It may be that the water is only a part of the stim and the soothing effect from the surroundings is a bigger part. If you take a recycling water approach there are a lot of people making mini kitchens for their kids with a recycling water setup there should be youtube tutorials you can adapt to a container.