The long soak, properly set up

A bath pillow lives or dies by its suction cups

It is a small thing that decides everything. A pillow with four large, soft cups on a smooth acrylic tub will stay exactly where you put it for an hour. The same pillow on a textured, slip-resistant tub floor will drift within minutes, and no amount of pressing will fix that — the cups simply cannot seal against a moulded pattern. So we tell people to check their tub surface before choosing, and we stock inflatable and moulded options for tubs where suction is never going to work. The same honesty applies to the water side: test strips tell you what is in the water, and they are only useful if you read them in daylight against the printed chart.