I've seen a few people saying they just sling loose hop pellets in without a problem. I just can't imagine how based on the gunk they create... I use a muslin bag to good effect and don't have any issues with the hop sediment.
After adding the hop pellets it bubbled away again for a few days but no discernible change in the gravity from 1010. Bottled it yesterday and discovered that amount of hop pellets leads to issues with bottling. Tried filtering using the Little Bottler but it kept clogging so eventually switched to a syphon with a boiled pop sock around the end in the fermenter. I think I managed to keep bits of hop out of the bottles - now to see whether it clears and conditions nicely.