No. they're called "bezoars" which exist in all sewer systems, including septic. which is why septic dudes exist.

They're a mix of skin and hair oils, soap, and excreta, that form a giant gob inside of the sewer pipe.

It's the same name you give to little kids that have a nervous hair chewing tic and develop a similar blockage.

Jizz isn't involved. If you've ever even watched jizz go down the shower drain, you know it's practically dissolved and destroyed before it even starts to circle.

Like, disregarding incel bullshit. If jizz was concrete, we'd have been making buildings with it since the neolithic. "Ay gurr, I got the concrete you need for them seams just flows way too smooth not to work.