I want to attach some suction cups to a surface, such as a ceramic tile. 

The suction cups tend to stick for a little while, but inevitably fall off sooner or later, possibly due to microscopic pores or uneven spots in the surface, or simply because those are bad suction cups.

How can I increase the adhesion, while still being able to easily remove them later on?

I have had this problem when attaching suction cups to various surfaces, such as ceramic tiles, plastic, even glass

What did not work:

 - Wetting the surfaces; even generous amounts of water, soap, or spit did not help.

 - washing both surfaces vigorously

 - strong pressure when applying the suction cup, removing all bubbles


Common workarounds such as gluing or nailing leave permanent marks. Double-sided sticky tape tends to fail quickly in the presence of water.

Ideal would be some sort of non-permanent glue

I am looking for a way to make suction cups suck just a little more.