use anything thicker then a pencil, washed and cleaned branches, a bunch of rope ect. remove a window screen wash it and prop it up on the far side of the shower at an angle... NOTHING WITH SMOOTH SURFACES!!!!!!! IE: bamboo. a textured surface is the only option for chams esp in water.
if you have a tree that makes sense to let your cham climb on, then prop the hose so it falls on the tree with low pressure, my chams LOVE IT
i see where you are coming from with the " if it aint broke dont fix it" view brad, but many keepers witness chams not only drinking from a dripper, but washing their eyes in it ect... It rains in nature, as well.
Other than stress ( which isnt always a bad thing ) what at the negative effects?
And on that note, i think a shower will provide a healthy amount of stree