As someone who's had enough of them to have a favorite flavor of prep solution (lemon gavilyte-c, which tastes to me like a very mild lemon meringue), a couple tips:
1. Mix the solution with HOT water 12 hours before you need to drink it, and then refrigerate for the 12 hours. This way it doesn't taste salty.
2. For your "clear liquid" diet, drink bone broth with avocado oil in it, alternating with some coconut water. Get some protein and fat calories in you so you're not starving and not spiking your blood sugar all over the place. If I add 50% to my regular calorie intake, I'm not even really noticeably hungry.