Same here, my first attempts were with ziplock bags as well. This got messy. It rained and it was windy. Wasted half of it. Later in better condtions it was a quite cumbersome. And it all got sticky. And this all after many hours in a dellusional state
That’s why I changed over to little plastic bottles. A few in the jersey pockets, a few taped to the top tube as shown in the picture above. Sufficient for loooong races. I can fill the drinking bottles while riding. Just add some water at the aid station and I’m good to go.