I used to use the kitchen sink or the laundry tub. I've always showered with Darcy, and now she prefers it to the bath - she hogs the water and it's hard to get her out, but she's also cool with the pool and the bath. She's a toddler now and just plays in the bottom while I shower. She knows how to put the washer over the drain hole to block the water and pulls at my toes until I put my foot on the washer lol.
So ultimatley no I don't think you need a real bath....I was to short to have the baby bath anywhere except the floor so back wise I found my other options better....