Game version: 0.C-7138
Operating system: Windows
Tiles or curses: Tiles
Mods active: Default
As I remember, you could usually have a "bottle of disinfectant" in your inventory, on the ground or generally nearby, them press "a" and have it show up on the "Use Item" GUI, that shows various default options for different tools, foods, etc.
As you press "a" and look for the bottle of disinfectant, it isn't there.
You need to open the inventory, choose the bottle and them "apply" for it to work.
As described above.
Possibly related to #22943 ?
And it shows at the eat menu.
Also there are other strange things in the Eat Menu, like "pack with cigarette". IIRC it used to show up on "apply" menu.
Bottle of disinfectant doesn't show up on "% - Execute which action" but,
Pack of cigarette shows properly associated to "Smoke" action.
Since Leland requested for me to move relevant information here, here's my post from referenced duplicate issue:
I just tried it, can confirm earlier issue. Unbottled disinfectant you can spawn through debug menu indeed works, but the liquid-only disinfectant I cannot get out of bottle without pouring it out (the most common kind I found) still doesn't show in the 'a'ctivation menu.
Picture related, showing activation menu shortly after creating a randomized debug character in a fresh world (only DDA core active in a modlist), entering hospital and picking a bottle of disinfectant while having debug-spawned disinfectant in the inventory. Only the latter is shown.

And the picture ensuring I had both 'types' of disinfectant in the inventory, in number of portions indicating that again, only unbottled disinfectant is recognized through activation menu.

Happening also in the recent version (0.C-27468), will update the issue description.
Lastly, since I already made it, I can as well include the savegame.
This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. Please do not \'bump\' or comment on this issue unless you are actively working on it. Stale issues, and stale issues that are closed are still considered.
Just tested and this appears to work now. Spawned first aid kit, used it and then opened use item menu. small plastic bottle of antiseptic was present as an option
Ok, closing until reconfirmed.
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And it shows at the eat menu.