Good article, but you left out\ one of THE most important things: Advance preparation.
It’s real simple. But (no pun intended), it takes a little practice.
Here’s what you do: You start by carefully injecting (squirting) some comfortably warm water up your butt hole. You can do this with an enema, a shower nozle that can focus to a stream, a hose that slips onto the basin spout, or even just an empty shampoo bottle (really cleaned out, of course). Oh, yeah, and you should be sitting on the toilet, or in the shower… Then, you ‘expell’ it. Then do it again, and again; until you’re clean.
It will make your ‘getting fucked’ experience SOOOOOO much better — for both of you!
But, it takes practice. And keep your posture up well while you do it. It just helps…

One of your biggest fans,
Scott