Thanks for the replies guys. More curious than concerned. I'm fermenting in a bucket with a spigot on it, no secondary. Not wanting to take the lid off, I'll be removing the airlock and putting the pellets in via funnel through the hole in the lid. The existing trub is just below the spigot, so not too worried about solids carryover. I typically bottle the first quart of so to remove 'most' of the trub then fill the keg.
The paint strainer on a collar is great for boiling, use it for the multiple additions wihout having to clean a bunch of bags.