First I would ask, is there a reason? are your snakes having problems?
Then I would ask, If you want to add to your animals lifes, there are a million known ways to do that. Ok, not a million, just a lot of ways.
My own personal approach is to seek conditions where the snakes do not drink regularly. Again that old "in nature thing". In nature, many of our species, including kings, rarely are exposed to drinking water. And do seek mirco habitats that support hydration without the need to drink.
Its not about drinking water itself, in the field we watch snakes for months at a time with NO AVAILABLE DRINKING water, yet they are fine and going about daily behavior. The question is, can you take your water bowl out of your cage and have normal activity for months at a time. Which in most cases is no you can't. Doing so would result in a dead snake. Which brings up the question, why? (my actual point)
The only negative effect of adding your juice that I can think of, is, it could offset the acid/alkaline balance within your snake. Then consider, ovum and sperm are maintianed inside your animals, in a particular fluid. The health of that fluid is critical.
If adding your juice can be deterimed to improve, say fertility, that you have something there. Or the other side of the coin, increase infertility, that would not be good.
Also, no benefit and no harm, brings up the question of why? Why do needless things and back to the top, when there are things that are needed. Best wishes