You may want to consider Dipper likes to lick not just the water but as humans we have salt in our skin! . As humans we need some salt in our diets so do animals!. Paul my Partner is an RN and he said dogs and cats love the the taste of salt that is why they like to lick us! Oscar & Sam do the same!. In reference to the Bath mat you need to catch him in the act of stealing it!. Saying something after the event will not help my Breeder used the word  "Associate" a lot when you see Dipper doing it you say no right there and then he will after a while associate that he is not meant to steal the bath mat!. If you do it after the event doing it is fruitless as Dipper will not associate unless you do it at the exact time he's doing it Good luck!.