coconut shell bangle

hi mummies! my 9mo has been having nightmares and will be screaming in his sleep.. i was thinking of letting him wear the coconut shell bangle but i’m afraid that when i want to take it out, it’ll hurt him.. any other amulets etc to recommend and where to get it from..? if i were to get a coconut shell bangle from shops do i have to bring it to the temple & pray or can just straight away wear?