40 years as a Plumber/Pipefitter doing mostly Plumbing work I know how you guys feel. I have no olfactories, I can't smell anything.
My very first job as a new Plumber was on a plugged sewer. All the houses up on a hill was stopped up. Someone had to go down the first dry manhole and push the sewer snake up the pipe. Being the only One Stripper on the crew, I got the job. I climbed down a 15 ft manhole. Shoved the snake up the pipe about 8 ft when I heard a rumble. I reached up and grabbed the steel rung mounted into the wall to climb out. It broke, and I fell on my behind. That's when it all hit me. The men up on top were unable to do anything but watch, as I swirled around the manhole. Up and up I went, as I swam to stay on top. When I got high enough one of the guys reached down and grabbed my hand and lifted me out of the stuff. They led me over to a house and hosed me down. I stripped down and one of the residents handed me a pair of shorts. I changed into the shorts, but they still made me ride in the back of the truck back to the shop. I never saw that uniform again. Fortunately one of the men had taken my wallet and keys before I went down the hole, saying I might snag my pocket on something and lose them as I went down.
Toilets are usually very simple, you just have to take a good look at what they are or aren't doing.