Enemas work really well at cleaning you out. I'd recommend getting some but check to see what's in it before using it. Generally, replacing the saline solution with just warm water is recommended, otherwise it might cause an "incident". They often have an effect that causes your body to try and get rid of anything in there. Great for when you're blocked up, but if you're planning on anal then you might feel the need to go at an in-oppertune moment.
Also try earing plenty of fiber the day before if possible, it'll make movements easier and more clean. When you have the proper amount of fiber, poop sticks to itself better and it makes passing it easier and less messy as well.
I think they're referring to the title of the lemmy post, not the one in the image