YMMV, but I find that the 20-22 hour point is the hardest time for me in a 24, 36-hr or longer fast, but if I have some salt or bone broth and can make it to 23 hrs, it gets easier again (not always, but when my hunger disappears again I fast longer, if not, I eat some keto food). Luckily I like salt mixed with water and think of it as a nerve-synapse and energy restorer as I swallow it and imagine that it is the feeling a vampire would get when sucking blood. Swishing salt water around your gums and other mouth parts is good for them too (required when recovering from periodontal surgery). Follow the glass of salt water with a glass of plain water. You may only need one or two doses of salt to get over the hump, not continuous drinking of things you loathe for the rest of the fast.