I use very intensely-flavored fermented drinks like Kombucha. The electrolytes in them are also beneficial since Epsom Salts give me some diarrhea. There is a new brand of drinks I like: "Farmhouse Culture Gut Shots." They have a salty, savory taste to them, unlike the sweet taste you get from a lot of flavored kombuchas. The salty/savory flavor masks the bitter Epsom Salts better than any fruit juice.
I sipped the Epsom Salt solution, the first time I used it, just to see what it tasted like, and after I added two ounces of "Gut shots" to the mixture, I couldn't taste the bitterness at all. It totally hides the awfulness!