Hahah so wait how does the syringe idea work without it running out of your anus? wouldnt you have to lie on you back with your knees on both sides of your head type of deal, like a pile driver type of thing.
Most people shoot the contents of the syringe into the asshole while laying on one side, with one leg extended, one leg bent toward the chest. I'm not sure if it was mentioned in this thread, but for plugging, a simple oral medication syringe (no needle) or pet's oral syringe (again, no needle) is the perfect tool for plugging.
I have never had to lay on the floor for 20-30 minutes to make sure the "solution" stays in there. It just does. The butthole is designed to keep things in. Otherwise, many people would be spewing shit randomly out their asses at inconvenient times.
It is true that the bodies of some first-time pluggers confuse the feeling of having liquid in their butt with needing to take a shit. I only experienced this the first time and a bit of mental concentration banished the thought and I was good to go. I used techniques learned through yoga meditation and visualization practice.
To the poster above who laughed at the idea of using KY to lube the syringe, what is unusual or funny about that? If you're going to insert something into your asshole (which is very tight, cf. paragrah above), a little lube helps.
I hope you haven't tried anal sex yet. Because you're in for a big surprise if you think that things slide easily in and out of the asshole without the help of lube. The asshole is not the vagina: it does not self-lubricate. The lube needn't be KY or astro-glide, even a pure Aloe Vera Gel will work well, but be sure that you're using a product that contains no adulterants that will irritate the area.