I was pretty sure it has to do with sailing. I've heard it as "three sheets TO the wind". I wonder if that's regional?

The European/colonial contact with Mexico was from Spain, on Brazil was from Portugal. Different countries, different languages. Real in Spanish means royal. Other countries have currency terms related to their royalty, mostly the crown as a monarchistic symbol. England used the term "crown" for specific coins at various times. In Scandinavian countries, it's the local form for crown - kroner, krona, krone. The Czech Republic still uses koruna.

And all this time I thought it was a brand of household soap. Tsk.

And for those of us who didn't know: Snuff is a smokeless tobacco made from ground or pulverised tobacco leaves. It is inhaled or "snuffed" into the nasal cavity, delivering a swift hit of nicotine and a lasting flavoured scent (especially if flavouring has been blended with the tobacco). Was that the same as "take a powder"? Or was the powder something else?