I'm looking at building a hose attachment (chamber) that I can stuff with comfrey leaves, and some good compost to fertilize my garden some (force water through a pipe with small holes: https://www.youtube.com/watch?v=NOpvLFwjS1g), but not clog my watering stick (PVC pipe with lots of holes to distribute water pressure). How can I make a chamber that will prevent pipe clogging with hardware supply equipment? Is this even possible?
What you're looking for is called compost tea. The compost is placed in a barrel of water and aerated, then the solids are filtered out. The resulting water can be used in an agricultural sprayer to fertilize fields. Harvard uses and promotes it extensively if you're looking for more information.
At home sized scales you can use aquarium pumps and aerators, along with pantyhose filters.