Yep. I mix 10g glycerol with 30g water. I used it about 90min before a contest for vascularity. Stiock with the 30g water, taht way the right amount is stored in the plasma without the bloating. I never got side effects, provided i stuck with the amounts above.
The recommended serving size is about 1 gram per kilogram of bodyweight diluted in 20-25 milliliters of water. So if you weigh 80 Kgs, you would take 80 grams in 1600 - 2000 milliliters of water. Just for reference, 1 tablespoon is approximately 15 grams.
You should take it somewhere between 1 - 2 hours before your intended purpose.