So I bought two more hotwater bottles, these on Amazon. They are not in rubber but in some form of plastic. The blue one is from Ohuhu. The green one from another vendor. Both were under $15 and they don't stink like the old rubber bottles. Some reviewers say they stay hotter than the rubber, I say it's about the same.
I love having two hot water bottles, one for my tummy and one for my back when Terry works nights at the hospital. Keeps me warm and comfortable. I bought a couple more mostly for camping. In April or October, a hotwater bottle in the sleeping bag 30 minutes before bedtime can make it far more comfortable.