stubborn nappers

How do you get your baby to nap once you start breastfeeding less? I've started feeding my son purées twice a day so when he gets sleepy after that I don't want to nurse him to sleep because he spits up a lot. He's stubborn so rocking him takes forever because he just keeps wanting to nurse. I can put him in the swing if we're home or else I'm better just having someone else rock him. Just wondering how others handle it.