I shampoo my piggies in the kitchen sink or bath tub and have a bowl or 2 of clean warm water for rinsing laid out on the draining area. One reason I like the kitchen is that I have a mixer tap there so it is easy to rinse the pigs off by holding them underneath it. The temperature of the room is also normally warm. There is also more work surface space so I can lay out a multitude of dry towels ready for if I'm doing a multiple bathing session. A matter of what works for you. If your piggy is a bit of a 'leaper' you might want to bathe her in a washing up bowl sited in the bath so if she leaps out she hasn't far to fall. You can line the bath with an old towel so she doesn't slip about and hurt herself if she jumps out of the bowl.