I'm from outside of Kerala. But I can say yes these type of things like brainwashing happens in Bengal too . U would find many Muslim scholars in Facebook insulting Hindu Gods, Buddha and jesus. They don't talk about their own religion but always they tried prove that the practices in the Hinduism is so low ... By insulting others religion they tried to prove that their religion is best.
Some people from Bengal also converted and joined isis in past. There was a case of woman too .
A Bengali woman Ayesha ( name after converted)
Pre conversion name: Pragya
She was an undergraduate student when she went missing from West Bengal.
She was found in Bangladesh, converted, and arrested in Dhaka for having terror links with terrorist organization Jamaat ul Mujahideen Bangladesh (JMB)