I hate to break it to you, but there's been plenty of good measurements made of percentage of contents. There's faint traces of pee lingering in the urethra that semen can flush out.

Squirting begins with a release of urine from the bladder. The majority of it is urine. It's not a question, it's not a maybe, it's a confirmed fact.

There's nothing wrong with that. It's not a bad thing that it's almost all pee.

Now, it is also true that the vagina can produce a significant amount of exudate that can be ejected during orgasm. However, that isn't what's being claimed as squirting in any sense of the word. It's also not going to go flying into the face of sometime someone providing manual stimulation.

Nor can the skeene's gland send fluids flying.

And, again, squirting being urine isn't a bad thing. I'm not sure why people get all butthurt over it. It's still a sign of a powerful orgasm. It's still apparently a very pleasurable event for the person squirting. It doesn't change any fundamental fact of it being a good thing. It's just fucking piss, and while that might need cleaning up when it happens so does anything else produced during orgasm.

If it's the idea of piss, well, everyone can get the fuck over it. Piss isn't some unholy, horrible thing. When it comes right down to it, it's no more or less "icky" than vaginal exudate, semen, or the skin of the genitals, and we as a sexual species tend to dive face first into those, usually with glee. If you're sucking cock or eating pussy, there's already very faint traces of urine there unless you're in the shower while doing it, or are in the window between bathing and urination.

And, for the record, nobody referring to squirting is talking about a small burst of fluid measuring in the single cc or two range. They're talking about the giant geysers of fluid that pump out during an orgasm. The kind of thing you see in porn, which is where the vast majority of people have seen it. And that is absolutely, 100% not coming out of a gland. That is a release of urine that picks up some fluids along the way, which is the reverse of semen.

I'm sorry to be harsh, but for fucks sake, people are so fucking stupid accept this subject and there's no reason to be.

Idk if you've tried peeing after ejacalating as a man, but the pee doesnt work when the balls are talking. Idk if you've got some sort of traumatic injury that interferes with that process, but thats the reality for healthy anatomically intact males.