Kelantan has some crazy rules but you can definitely drink to excess in a tourist hotel or on the islands without any concern. The Perhentians is certainly not a pious place of purity, it gets fairly loose there.

> If you ever get yourself arrested in such a country make sure to contact a lawyer.

Not getting arrested in the first place is what you should really be doing. In basically all of South-East Asia on-the-spot fines are routine and expected. If you don't go that route and it hits the books you are in for a world of trouble and no amount of coffee money will save you. Not endorsing this, simply saying that's how it works.