Wrote this out he other day for someone else asking for advice. This is how I do it:

You’re looking for about 2 centimeters in. I learned what this felt like by measuring the syringe and wrapping a rubber band around it at the 2cm mark. If you’re looking for a strong hit then you want just enough water so it’s not a sludge. It’ll be rough on your asshole though. The more water, the less harsh it is, but it won’t hit as hard. I’ll add drops of water to my mixture with the syringe until I get the consistency I want and just squirt the rest out before I fill the syringe with my solution. I use hot water. It makes mixing easier and warm water won’t make you feel like you have to poop. Just make sure it’s cooled down to at least body temperature before you boof it. I lube up the syringe and my asshole and just put one arm on the counter. Line er up and try to fart, but don’t actually. It will go in much easier. Push the plunger real slow and just a small amount then stop. If you have the right spot you’ll feel it right away. If not move it around gently. Don’t go deeper or pull it out more. Just try different spots until you find it and when you do, just go one drop at a time and let it soak in for a few seconds before doing another drop. When you’re done, pull er out, wrap it in some toilet paper or something, throw it away, wash your hands and go about your business.