hot glue and silicone are the ways to go.

i would use one of the two and just glue the wires right in. if something needs to be changed you will need to rip it out, but its not too much work to redo it afterwards.

with both, they get waterproof, so when you manage to get a nice smooth surface you can clean right over it. most importantly, unlike tape, after a while the stickiness completely goes away as the stuff hardens.