I have one I use occasionally. They tend to limited by the hole size in the injection needle. herbs, bits of garlic clog thme up.
It's best to prepare the injecyion early so it has some time for flavors to permeate the liquid, then strain through cheesecloth before you inject.
forgive my typos, I'm on myxoom which is no fun to type or edit on. But otherwise very fun and useful.