I've been cleaning my own sensors for well over a decade. Visible Dust products are head and shoulders above others. Yes CPS will clean a sensor, but you are without your camera and shipping gets pretty expensive, because dust comes back on a regular basis.
Done carefully, there is virtually no chance of damaging your sensor. Visible Dust has plenty of video tutorials to walk you through it. A key is hold the swab vertically for a few minutes after you place a couple of drops of Sensor Clean on the leading edge of the swab, this allows the liquid to soak in, and evaporate a little. One pass down the sensor, rotate it 180 degrees and make another pass in the same direction. Look at the sensor with a Visible Dust sensor loupe, shoot the sky at f16, see if you got it all. If you did, great, if not repeat until you do.
Very little pressure is required/suggested. Once you get the hang of it, you'll wonder why you ever went through the time and trouble to send it off. I have four or five bodies at any given time. I had to learn to do this.
I do my own as well, but I also see a lot of posts from failed cleanings. The devil is in the details. Done properly is a nebulous term, not every one has the dexterity or manual skills. Some people think more is better and douse the swab with cleaner. The cleaner runs under the AA filter, and its a mess. Some rub too hard and scratch or otherwise damage the surface of the AA filter. And some reuse swabs and end up putting more junk back on the sensor.
Never underestimate a fool, we are just too clever.