is there any video guide I could watch for help?

at least 5 of these achievements are wrong/misleading

Very important tip from TheLimeyDragon concerning "Little Mucky Pup". I was already at the church and loaded an earlier save. When I used the ketchup with Dr. Marcel's painting I got the achievement.
"Waterplacer": I gave a water cup to Stiesel and threw another one off the roof, then the achievement unlocked for me. They don't need to be filled with water, just use the empty ones.

thanks for the guide!
for the "comic nerd" and "big litterbug" achievements, does "everything" refer to all the static objects in-game, or also to other items in the inventory?
also, so far I had no luck filling the flithy cups on any of the water sources... does it have to be a specific one? because every tap I've tried just destroys the cup.

I also had problems with the water placement achievement.

Another guide online said to place them in these exact spots:

The fireplace in Dr. Marcel's office.
The chair in front of Edna's cell.
Give one to the guard who chased you on the roof.
Put one back into the trash bin.
In the oven in the basement.
On the sofa near the telephone on first floor.
Give one to the professor in the TV room.

I started the game again, and when I placed the 5th cup in that list the achievement popped.

Also had an issue with "Little Mucky Pup" even tho I got the "Big Litterbug" achievement. I also found a list of things needed to be 'hit':

Table in Edna's cell
Dr Marcel's Desk
Dr Marcel's Diploma
Dr Marcel's Trophy Cabinet
Washbasin in break room
Washbasin in WC
Washbasins in bathroom
Dr Marcel's Portrait (Ground Floor)
Birdbath


I was just missing "Dr Marcel's Portrait".

I didn't have any issues with the waterplacer achievement.
I just placed placed seven soaked and filthy cups.
Maybe you can try to verify game's files on Steam and try it again.
Good luck and thanks for your feedback.

This guide does not include unmissable achievements, to keep it simple and spoiler free.

Escaperess and Lady of Keys are not included in your list of achievements. It would be awesome if you could add those for everybody. Thanks so much for all your efforts to make your guide. I am grateful to all of you Guideance Counselors. Cheers!!

It's unfair I tell ya, all that hard work and sweat for nothing but the jokes heard via the trial and error process!!!! I think I tried the cup on every clickable item. All those trips to the control room... How many miles did I walk? My wrist aches from all the clicking. Ergh!!

Does anybody else have the problem of the Waterplacer achievement not popping up? I placed 3 cups Mattis's office: one in the fireplace, one in the drawer, one in the closet, dribbled water from the cup on his desk and chair, the pillow in his son's shrine, on other furniture, placed by various potted plants, (including the guard room, both of the plants in the TV room, the hallway by the recreation room-the one with the phone, a plant in the hallway next to the WC), as well as 3 on the shelves in the attic, one in the cupboard in the room with the gumball machine, one by the chair in the room with the prison cell, one by the chair in the TV room, one the shelves in the room where Beeman sits, one on the barstool in the bar, the shelves in the bar, and finally, the drawer in the room with the patient records, next to a pair of laundry bags along the laundry transit. That's 21 placed cups, 3 times 7 cups!!!! I kept hoping.