I didn't like them myself I found them a little too aggressive on the pile in places. My personal favorite way is to agitate in using a shampoo brush then go over with a bonnet. But if you want to give them ago I have a couple I would sell you.
However quick and visually effective encap is on carpet tile etc.. i still feel like I'm only doing half a job, especially times when i extract and see what I would have left behind.