I'm wondering if anyone has any success in making a homemade gunge tank. This is very raw and haphazard but today I balanced a large funnel over my shower, which was balanced through a piece of cardboard.
I then placed a ballon over the end to hold the gunge in, with a piece of string attached to it. I carefully filled it up, FaceTimed a girl friend of mine who asked me quiz questions. When I lost I pulled the string and hey presto! It worked like a treat and was really intense!!
Balancing is never a good thing when you have a weight and a pointed if blunt piece of plastic above your head. If that falls it's basically; your head, funnel point, weight of balloon pushing down.
Never suspend anything over your head that could hurt you. Especially using cardboard that is no exactly structural.
Personally I use a scaffold (see the pictures in my profile), the heavier something is the more dangerous it is. Depending on room, maybe use 2 ladders and a strong plank of wood with a hole drilled through it for the gunge/mess? Put a paddling pool underneath and a shower curtain to contain the splash.