you can also hold lectures at university for int, will and influence.
the chances however are so low, that even with F5 its mindnumbing
Yeah for me anything with a chance in the 1% or less range is just not something I'm going to do unless it's something like combat skill increases where you have so many attempts that the low chance doesn't matter. The chance needs to be at least 10% for me to consider it viable to use for stat increases, preferably more like 20-25%.
For instance you can get science to 50 and academics to 80 drinking at the palace without using F5 in a somewhat tolerable time frame. You can also get manipulate to 90 via explain chores and explain sex duties in a somewhat tolerable timeframe without F5. Charm has always been trivial to get to at least 85 via surgery. Medical you can get to 90 just using doctor's kits and if you want to speed up the process you can grab 4 randoms and just run them through the meat grinder getting them taken down constantly in every fight on purpose just to grind up medical (much less of an option if you're playing iron man though).
So for me the main stats that are annoying to grind are Intelligence, artisan, blacksmith, bondage, and flagellation. Artisan and blacksmith are doable if you don't mind making mountains of combat knives. I prefer to start with the expert business skill class and the crafter perk so I don't have as far to go on that. Bondage and Flagellation there's really no option but to F5 it in the velvet room if you want to eventually get those to 100+ (they both cap at 70 in the velvet room and then you can take the bondage class and read the books to get past 100).
Ironically the academy and the historical society, which you would think should be the best options for intelligence, academics, and science are actually the most grindy as far as I know so I never teach any classes or spend any time in the historical society. The historical society increases are actually guaranteed but require so many attempts for a single point that you're better off doing almost anything else that has a chance to raise the same stats. Maybe that will get rebalanced when an update focused more around Atheism/artifact hunting/etc goes in.