Unfortunately, it appears you misunderstand the function of Prestidigitation.
The trinket lasts approximately 6 seconds. If we assume a turn is 6 seconds, as is standard, and that you finish the turn after using Prestidigitation, you have through your next turn to use the glass. Basically, you have to fill and drink from the glass in the next 6 seconds. Possible? Yes, but not for what you’re doing unless you get the assistance of other casters.
Liquids aren’t really objects, according to DMG-246:
For the purpose of these rules, an object is a discrete, inanimate item like a window, door, sword, book, table, chair, or stone, not a building or a vehicle that is composed of many other objects.
While this could be considered nitpicky, water isn’t discrete. It’s a collection of detached units that work together. In a way, water is no different from a building or a vehicle as per RAW.
- Let’s say the trinket didn’t have a timer and that the water could be cleaned by Prestidigitation, though. Would this work? Kind of. While you certainly meet RAW for the number of non-Instantaneous effects that can be in-play at a time, your series of Prestidigitations has a specific drawback: the pina colada is still contaminated swamp water.
Prestidigitation only cleans the object; that is to say it only gets rid of that which makes it dirty, not diseased. Swamp water is full of chemical compounds that don’t fall under the purview of that which is “dirty”, or in the literal sense “dirt”. While we could certainly try to rationalize it as such, it’s best to imagine the spell as the most basic of water filters in this case. You’re getting rid of the dirt from the water, but anything like plants, bacteria, etc. that are in the water would remain. It’s still swamp water, but it’s “clean” swamp water, still unfit for human consumption.
In order to purify it to be water again, you need the spell Purify Food and Drink which will get rid of the bacteria, but not any plant-life that is in it. To get rid of the plant life, you’d have to run it through an actual filter of some kind, which can be done by putting the water in a container, strapping fabric over the opening, then putting fabric over the opening of an empty container, all before pouring the water from container a to container b. There. Now you finally have drinkable water, but even if you flavor and chill it, you don’t have a pina colada. All you have is water that tastes like it, but without any of the fun effects.
- “Have I just invented the most profitable tavern ever?” No, you haven’t. If you tried to use your method, you’d be making patrons sick left and right, assuming you didn’t scare them off by constantly spilling swamp water all over them thanks to your glass trinkets disappearing as soon as you set it in front of them. Not only that, but using your method as written, the most you can make is one glass’s worth of alcohol at a time due to the limitations of Prestidigitation.
If you cast this spell multiple times, you can have up to three of its non-instantaneous Effects active at a time, and you can dismiss such an effect as an action.
Alternatively, if you did this on a cubic foot of water and poured it into actual cups not made of Prestidigitation, it would get you 119 cups of 8 fl. oz. of pina co-swamp water, which would be far more profitable until Health and Safety shut you down for food code violations. Finally, let’s say you did get customers… They wouldn’t be happy that all your drinks are virgin (no alcohol). You may be able to make it taste like booze, but they’d realize that they aren’t getting drunk and then blame you for ripping them off.
In short, your plan doesn’t work, at least not in the way you intended and not with the method you described… but feel free to try.