All liquids come out everything else stays. Last year I forgot to remove my computer printer. Yes ink is a liquid and what a mess in the spring. Destroyed the printer and thank goodness the ink stains are hidden inside the desk. This year we are going to solve the problem by spending the winter in South Florida.
Much to my dismay I discovered that my jacks leave rust marks on my expensive stain finish on my pad in an owner RV resort. Plastic jack pad have stopped this problem. Also camped where my jacks sank into the mud several inches. I had to use a cow bar to pry my jacks free from the mud. Yes I use jack pads.