Blocking script

Are there any issues with using the block script for attempting to block multiple requests (from navigated domain)?

I have a blockDomains script blocking requests from multiple domains successfully, but my block script fails when putting in multiple entries following the documentation, e.g.:

block carousel-horizontal-posts-content-slider
navigate [domain]
= success

block carousel-horizontal-posts-content-slider collapse-o-matic
navigate [domain]
= both failing

Am I implementing this correctly?