I took the question literally: "What is the most cum you have swallowed?", not "What is the most number of cocks you have sucked".
To go along with the crowd...not usual for me... I have sucked 5 cocks off and swallowed their loads in one day. But as far as How much CUM... I saved all my loads from jacking to porn for a boring winter and kept adding it all to the same covered glass that I then put back into the freezer for the next load.
This went on all winter, probably 70 loads. All the hot, gooey cock cream spurted on top of the preceding, now frozen load. As it froze it created swirls of iridescent perl and globs of thick white strands.
Once I got to the top of the 12-ounce glass I decided it was time. So, with a 24-ounce mug of cold Scotch Ale I let the glass of cock cream slowly defrost in a pot of warm water. Checking every few minutes and replacing the warm bath as need it too almost 2 hours to completely warm back up to body temperature. By this time, I was on my second Ale had a good buzz so there was no stopping now.
Just in case I handled drink all that sperm like most of the Japanese porn girls did drinking their hug pitchers, I went to the bathroom. Positioned near the toilet I decided this was even better as I could watch myself in the mirror as I drank my 70 loads of sperm. I basically sipped and gulped my way down to half a glass before I had to burp. No problem, so I continued taking small gulps of the creamy cock juice into my mouth. I even grinned at my reflection and showed several mouthfuls to myself, swirling my tongue around it the warm goo.
I will have to admit that frozen cum does NOT taste as good as fresh. It tends to separate into white strands and a lot of thin, watery mix. About as expected given its components. I took down every drop and would do it again, but I would really like to try like the Japanese porn girls, to drink down a small pitcher, then maybe a large one.. but it has to be fresh. So where do I get 200 horny guys to suck hard until they are ready to cum, then jack them into the pitcher?
One can only dream....