Scale wont hurt your cham, but will eventually damage the plant. If its hard, brown scale, they are a pita bit less damaging than mealybugs (white, cottony scale). Any plant pest will eventually damage the plant, so they should be attemtped to be controlled. The sticky stuff is “honeydew” from where they were sucking on the plant, and it can attract ants.
My advice would be - don’t freak out. Take the plants out for your next cleaning day and spray them liberally (including underside of leaves and stem) with a mixture of dawn dish soap and maybe 2-3 tablespoons of 70% rubbing alcohol. I just eyeball it, but you should have a very sudsy spray that smells like alcohol. Spray the plant and let it sit for 5 mins, then rinse it witha good pressure of water very well. You should repeat this every 2 weeks until the problem is resolved or dramatically reduced. Then you can use a qtip with rubbing alcohol to spot treat any scale you see later.