I certainly didn’t learn to bash Catholics in a Methodist church.
Every Summer when I was a kid from 5th grade to high school age, I would go to a Methodist bible school. In middle school and high school, I volunteered as an aide for it. My parish priest knew about it and thought it was a wonderful idea to help children learn about Jesus. Never once did he advise that I should convert or even bring up the idea of Catholicism. So both the Methodist minister, the Methodist teachers and my RC priest all loved the idea and it wasn’t a big deal whatsoever.