Ziploc???

Thanks for posting this picture. I am inspired now seeing a visual of how to renovate our basement washroom :)

I agree with Cynthia. A simple stand would do the trick and also add color if one wishes.

add a bidet style toilet seat.

Still need paper...

Put a recess in the wall next to the toilet then use a commercial toilet paper holder the ones which have the curved metal piece, which you have to peer under to see if there is any paper. That should allow the water to roll off of it keeping the toilet paper dry. Also the flat ones(commercial) which hold two rolls, one in use and a back up, only you would most likely only be able to have one in at a time so you could push it up into the back up spot when showering. This should also keep it dry. Some moisture/water may collect on the floor of this type. Another option would be to recess a long narrow(size of toilet paper holder) pocket in the wall between the studs and place the holder in this. Then tile over the part where you have attached the holder. So you have left a pocket in the wall. If you can, place this high enough in the wall so that when you need to change the roll you do not have to get on your knees and twist your arm funny to reach it. Also be sure to slope the recess at the bottom so the water will flow toward the drain. Great question by the way. I love the idea but never considered the toilet paper.

Wash with shower head, no need paper!

The toilet paper holder is on the back of the door. Since the shower is used very infrequently, there is no need to remove it.