I think the amount of 'hooch' in our bars and shops must have diminished a bit as people these days insist of vaguely recognisable brands. Some of the Murcian imitations for example have disappeared, while Murcian Tequila, despite lots of cactus decoration on the label, must now be described as 'Licor Fantasía'.
It will give you a headache.
Gin Rollins (not, perhaps, one of the world's top brands) invented the 'unfillable bottle' thirty years back to stop bartenders re-filling bottles with garrafón. Now pretty much all Spanish booze incorporates the irrellenable top into its brands, as do many imported alcohols.
Bloody nuisence as a rule as you end up sloshing some of a new bottle down the sink.
Garrafón is rough stuff in a ten litre jug, or worse still, in barrels. It is sometimes available in dodgy bodegas and will be cheap.
Today, a group out of Murcia has been caught after importing garrafón rum from the Dominican Republic and bottling it in a fancy (fake) cuban brand with a 2,000% mark up.
Cheers!