Oh lol I was thinking he was gonna put the jar somewhere the sun doesn’t shine. There was an infamous video about that, circling the internet in the early days. I won’t bother you with the details, but the extended cut involved tweezers.
So. Once upon a time on a horrible place called 4chan, a dude got a glass jar and a Rainbow Dash figurine. He put the figure in the jar and then proceeded to cum into it repeatedly. His goal, for whatever reason, was to fill it to the top. Unfortunately this man was also stupid and kept the jar on his heater. During the winter the heat came on and the rainbow dash was effectively boiled in cum which ruined the entire ‘project’. So the man started again. He completed the project in 2017.